Visualizing HSIC Measures

import sys, os
import warnings
import tqdm
import random
import pandas as pd
import numpy as np

import matplotlib.pyplot as plt

# Insert path to model directory,.
cwd = os.getcwd()
path = f"{cwd}/../../src"
sys.path.insert(0, path)

# toy datasets
from data.toy import generate_dependence_data

# Kernel Dependency measure
from models.dependence import HSIC
from models.kernel import estimate_sigma, sigma_to_gamma, gamma_to_sigma, get_param_grid

# RBIG IT measures
from models.ite_algorithms import run_rbig_models

import matplotlib
import matplotlib.pyplot as plt
import seaborn as sns
%matplotlib inline

warnings.filterwarnings('ignore') # get rid of annoying warnings

%load_ext autoreload
%autoreload 2

fig_path = "/home/emmanuel/projects/2019_hsic_align/results/figures/distribution_experiment/"

save_path   = f'{cwd}/../../results/hsic/'
save_name   = 'dist_v2_belkin'

cols = [
    'dataset', 
    'trial', 
    'n_samples', 
    'd_dimensions', 
    'nu', 
    'std',
    'gamma', 
    'gamma_median',
    'gamma_silv',
    'gamma_scott',
    'gamma_belkin',
    'scorer', 
    'value',
    'mi_score'
]

results_df = pd.read_csv(f"{save_path}{save_name}.csv")[cols]

results_df.tail()

	dataset	trial	n_samples	d_dimensions	nu	std	gamma	gamma_median	gamma_silv	gamma_scott	gamma_belkin	scorer	value	mi_score
7495	tstudent	5	5000	100	20.0	NaN	0.275053	11.709883	0.893117	0.921368	8.754526	tka	1.000000	8.098041
7496	tstudent	5	5000	100	20.0	NaN	0.275053	11.709883	0.893117	0.921368	8.754526	ctka	1.000000	8.098041
7497	tstudent	5	5000	100	30.0	NaN	0.005442	11.549000	0.893117	0.921368	8.718251	hsic	0.025679	7.993998
7498	tstudent	5	5000	100	30.0	NaN	0.281852	11.549000	0.893117	0.921368	8.718251	tka	1.000000	7.993998
7499	tstudent	5	5000	100	30.0	NaN	0.281852	11.549000	0.893117	0.921368	8.718251	ctka	1.000000	7.993998

res_samples = results_df['n_samples'].unique().tolist()
res_dists = results_df['dataset'].unique().tolist()
res_dimensions = results_df['d_dimensions'].unique().tolist()
res_scorer = results_df['scorer'].unique().tolist()

Figure I - Gaussian Distribution

results_gaussian = results_df[results_df['dataset'] == 'gauss']

results_gaussian.tail()

	dataset	trial	n_samples	d_dimensions	nu	std	gamma	gamma_median	gamma_silv	gamma_scott	gamma_belkin	scorer	value	mi_score
4120	gauss	5	5000	100	NaN	0.9	0.285036	11.635845	0.893117	0.921368	9.328636	tka	1.000000	4.828360
4121	gauss	5	5000	100	NaN	0.9	0.285036	11.635845	0.893117	0.921368	9.328636	ctka	1.000000	4.828360
4122	gauss	5	5000	100	NaN	1.0	0.005679	11.299636	0.893117	0.921368	8.659846	hsic	0.026563	7.938746
4123	gauss	5	5000	100	NaN	1.0	0.294129	11.299636	0.893117	0.921368	8.659846	tka	1.000000	7.938746
4124	gauss	5	5000	100	NaN	1.0	0.294129	11.299636	0.893117	0.921368	8.659846	ctka	1.000000	7.938746

Figure I - T-Student Distribution

This first figure is to demonstrate how the mutual information compares with the amount of noise for each of the functions Linear, Sinusoidal, Circular, and Random.

results_gaussian = results_df[results_df['dataset'] == 'gauss']
results_tstudent = results_df[results_df['dataset'] == 'tstudent']


results_tstudent.head()

	dataset	trial	n_samples	d_dimensions	nu	std	gamma	gamma_median	gamma_silv	gamma_scott	gamma_belkin	scorer	value	mi_score
4125	tstudent	1	50	2	1.0	NaN	0.244634	4.263675	0.521001	0.521001	1.915118	hsic	0.026925	0.302042
4126	tstudent	1	50	2	1.0	NaN	0.000193	4.263675	0.521001	0.521001	1.915118	tka	0.999865	0.302042
4127	tstudent	1	50	2	1.0	NaN	1.934087	4.263675	0.521001	0.521001	1.915118	ctka	0.630722	0.302042
4128	tstudent	1	50	2	2.0	NaN	4.484111	2.444370	0.521001	0.521001	1.049202	hsic	0.018855	0.136519
4129	tstudent	1	50	2	2.0	NaN	0.000448	2.444370	0.521001	0.521001	1.049202	tka	0.999888	0.136519

Step I - Take the mean wrt the experimental parameters

def average_trials(res_df):
    # Take the average of the trials
    cols = res_df.columns.tolist()
#     cols.remove('trial')
#     cols.remove('value')
#     cols.remove('gamma')
    return res_df.groupby(cols).mean().drop('trial', axis=1).reset_index()

def variance_trials(res_df):
    # Take the average of the trials
    cols = res_df.columns.tolist()
    cols.remove('trial')
    return res_df.groupby(cols).std().reset_index().drop('trial', axis=1)

exp_vars = [
    'dataset', 
    'trial', 
    'n_samples', 
    'd_dimensions', 
    'nu', 
    'std',
    'gamma', 
    'gamma_median',
    'gamma_silv',
    'gamma_scott',
    'gamma_belkin',
    'scorer', 
    'value'
]

cols = results_tstudent.columns.tolist()
# cols.remove('trial')
# cols.remove('value')
# cols.remove('gamma')
res = average_trials(results_tstudent)

res.head()

---------------------------------------------------------------------------
DataError                                 Traceback (most recent call last)
<ipython-input-10-30ea35f40b59> in <module>
     18 # cols.remove('value')
     19 # cols.remove('gamma')
---> 20 res = average_trials(results_tstudent)
     21 
     22 res.head()

<ipython-input-9-b503816a108f> in average_trials(res_df)
      5 #     cols.remove('value')
      6 #     cols.remove('gamma')
----> 7     return res_df.groupby(cols).mean().drop('trial', axis=1).reset_index()
      8 
      9 def variance_trials(res_df):

~/.conda/envs/it4dnn/lib/python3.6/site-packages/pandas/core/groupby/groupby.py in mean(self, *args, **kwargs)
   1203         try:
   1204             return self._cython_agg_general(
-> 1205                 "mean", alt=lambda x, axis: Series(x).mean(**kwargs), **kwargs
   1206             )
   1207         except GroupByError:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/pandas/core/groupby/generic.py in _cython_agg_general(self, how, alt, numeric_only, min_count)
    126     def _cython_agg_general(self, how, alt=None, numeric_only=True, min_count=-1):
    127         new_items, new_blocks = self._cython_agg_blocks(
--> 128             how, alt=alt, numeric_only=numeric_only, min_count=min_count
    129         )
    130         return self._wrap_agged_blocks(new_items, new_blocks)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/pandas/core/groupby/generic.py in _cython_agg_blocks(self, how, alt, numeric_only, min_count)
    186 
    187         if len(new_blocks) == 0:
--> 188             raise DataError("No numeric types to aggregate")
    189 
    190         # reset the locs in the blocks to correspond to our

DataError: No numeric types to aggregate

def plot_prepare(res_df, dataset='gauss'):

    # grab dataset attributes (fixed variables)
    d_dimensions = res_df['d_dimensions'].unique()
    n_samples = res_df['n_samples'].unique()
    dataset = res_df['dataset'].unique()

    gamma_scott = res_df['gamma_scott'].unique()
    gamma_silv = res_df['gamma_silv'].unique()
    gamma_median = res_df['gamma_median'].unique()
    gamma_belkin = res_df['gamma_belkin'].unique()
    scorers = res_df['scorer'].unique().tolist()
#     print(gamma_median)

    # get fixed variables
    if dataset == 'gauss':
        fixed_vars = {
            'd_dimensions':int(d_dimensions),
            'n_samples': int(n_samples),
            'dataset': dataset,
            'scorer': scorers,
        }
    elif dataset == 'tstudent':
        fixed_vars = {
            'd_dimensions':int(d_dimensions),
            'n_samples': int(n_samples),
            'dataset': dataset,
            'scorer': scorers,
        }
    else:
        raise ValueError(f'Unrecognized distribution {dataset}')
    return res_df, fixed_vars

def plot_gauss(res_df, fixed_vars, save=True):
    for iscore in res_df.groupby('scorer'):
#         print(iscore[1].head())
        mean_results = iscore[1].groupby(['dataset', 'd_dimensions', 'scorer', 'std']).median()
        std_results = iscore[1].groupby(['dataset', 'd_dimensions', 'scorer', 'std']).std()
        mean_results['hsic_std'] = std_results['value'].values
        mean_results['mi_std'] = std_results['mi_score'].values
        mean_results = mean_results.reset_index()
#         break
#         print(mean_results.head())
        fig, ax = plt.subplots()
        pts = sns.scatterplot(
            x='value', 
            y='mi_score', 
            data=mean_results, 
            size='hsic_std',
            sizes=(50,200),
            ax=ax, 
            hue='gamma', 
#             hue_norm=matplotlib.colors.LogNorm(),
            label=iscore[0].upper(),
            palette='Spectral'
        )
        ax.legend([str(iscore[0])])
        ax.set_xlabel('HSIC Value')
        ax.set_ylabel(r'Mutual Information')
        ax.set_title(
            f"D: {int(fixed_vars['d_dimensions'])},"
            f" N: {fixed_vars['n_samples']},"
            f"{fixed_vars['dataset'][0]}"
        )

        # COLORBAR
        norm = matplotlib.colors.LogNorm(mean_results.gamma.min(), mean_results.gamma.max())
        sm = plt.cm.ScalarMappable(cmap="Spectral", norm=norm)
        sm.set_array([])
        pts.figure.colorbar(sm, label=r'RBF Bandwidth, $\gamma$')

        if not save:
            plt.show()
        else:
            save_name = \
                f"{fixed_vars['dataset'][0]}_" + \
                f"{int(fixed_vars['n_samples'])}_" + \
                f"{int(fixed_vars['d_dimensions'])}_" + \
                f"{int(fixed_vars['std'])}_" + \
                f"{iscore[0].upper()}" + \
                ".png"

            fig.savefig(fig_path + save_name)
    return None

def plot_tstudent(res_df, fixed_vars, save=True):
    for iscore in res_df.groupby('scorer'):
#         print(iscore[1].head())
        mean_results = iscore[1].groupby(['dataset', 'd_dimensions', 'scorer', 'nu']).median()
        std_results = iscore[1].groupby(['dataset', 'd_dimensions', 'scorer', 'nu']).std()
        mean_results['hsic_std'] = std_results['value'].values
        mean_results['mi_std'] = std_results['mi_score'].values
        mean_results = mean_results.reset_index()
#         break
#         print(mean_results.head())
        fig, ax = plt.subplots()
        pts = sns.scatterplot(
            x='value', 
            y='mi_score', 
            data=mean_results, 
            size='hsic_std',
            sizes=(50,200),
            ax=ax, 
            hue='gamma', 
#             hue_norm=matplotlib.colors.LogNorm(),
            label=iscore[0].upper(),
            palette='Spectral'
        )
        ax.legend([str(iscore[0])])
        ax.set_xlabel('HSIC Value')
        ax.set_ylabel(r'MI (nats)')
        ax.set_title(
            f"D: {int(fixed_vars['d_dimensions'])},"
            f" N: {fixed_vars['n_samples']},"
            f"{fixed_vars['dataset'][0]}"
        )

        # COLORBAR
        norm = matplotlib.colors.LogNorm(mean_results.gamma.min(), mean_results.gamma.max())
        sm = plt.cm.ScalarMappable(cmap="Spectral", norm=norm)
        sm.set_array([])
        pts.figure.colorbar(sm, label=r'RBF Bandwidth, $\gamma$')

        if not save:
            plt.show()
        else:
            save_name = \
                f"{fixed_vars['dataset'][0]}_" + \
                f"{int(fixed_vars['n_samples'])}_" + \
                f"{int(fixed_vars['d_dimensions'])}_" + \
                f"{int(fixed_vars['nu'])}_" + \
                f"{iscore[0].upper()}" + \
                ".png"

            fig.savefig(fig_path + save_name)
    return None

plot_groups = ['dataset', 'n_samples', 'd_dimensions', 'dataset', ]

subres =  results_tstudent.groupby(plot_groups)

for igroup in subres:


    igroup, fixed_vars = plot_prepare(igroup[1])

    t = igroup

    plot_tstudent(igroup, fixed_vars, save=False)
    break

plot_groups = ['dataset', 'n_samples', 'd_dimensions', 'dataset', ]

subres =  results_gaussian.groupby(plot_groups)

for igroup in subres:


    igroup, fixed_vars = plot_prepare(igroup[1])

    t = igroup

    plot_gauss(igroup, fixed_vars, save=False)
    break

for igroup in subres:


    igroup, fixed_vars = plot_prepare(igroup[1])

    t = igroup

    plot_tstudent(igroup, fixed_vars, save=False)

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/formatters.py in __call__(self, obj)
    339                 pass
    340             else:
--> 341                 return printer(obj)
    342             # Finally look for special method names
    343             method = get_real_method(obj, self.print_method)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in <lambda>(fig)
    242 
    243     if 'png' in formats:
--> 244         png_formatter.for_type(Figure, lambda fig: print_figure(fig, 'png', **kwargs))
    245     if 'retina' in formats or 'png2x' in formats:
    246         png_formatter.for_type(Figure, lambda fig: retina_figure(fig, **kwargs))

~/.conda/envs/it4dnn/lib/python3.6/site-packages/IPython/core/pylabtools.py in print_figure(fig, fmt, bbox_inches, **kwargs)
    126 
    127     bytes_io = BytesIO()
--> 128     fig.canvas.print_figure(bytes_io, **kw)
    129     data = bytes_io.getvalue()
    130     if fmt == 'svg':

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backend_bases.py in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, format, bbox_inches, **kwargs)
   2054                         orientation=orientation,
   2055                         dryrun=True,
-> 2056                         **kwargs)
   2057                     renderer = self.figure._cachedRenderer
   2058                     bbox_artists = kwargs.pop("bbox_extra_artists", None)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in print_png(self, filename_or_obj, metadata, pil_kwargs, *args, **kwargs)
    525 
    526         else:
--> 527             FigureCanvasAgg.draw(self)
    528             renderer = self.get_renderer()
    529             with cbook._setattr_cm(renderer, dpi=self.figure.dpi), \

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/backends/backend_agg.py in draw(self)
    386         self.renderer = self.get_renderer(cleared=True)
    387         with RendererAgg.lock:
--> 388             self.figure.draw(self.renderer)
    389             # A GUI class may be need to update a window using this draw, so
    390             # don't forget to call the superclass.

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/figure.py in draw(self, renderer)
   1707             self.patch.draw(renderer)
   1708             mimage._draw_list_compositing_images(
-> 1709                 renderer, self, artists, self.suppressComposite)
   1710 
   1711             renderer.close_group('figure')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/axes/_base.py in draw(self, renderer, inframe)
   2645             renderer.stop_rasterizing()
   2646 
-> 2647         mimage._draw_list_compositing_images(renderer, self, artists)
   2648 
   2649         renderer.close_group('axes')

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/image.py in _draw_list_compositing_images(renderer, parent, artists, suppress_composite)
    133     if not_composite or not has_images:
    134         for a in artists:
--> 135             a.draw(renderer)
    136     else:
    137         # Composite any adjacent images together

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/artist.py in draw_wrapper(artist, renderer, *args, **kwargs)
     36                 renderer.start_filter()
     37 
---> 38             return draw(artist, renderer, *args, **kwargs)
     39         finally:
     40             if artist.get_agg_filter() is not None:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in draw(self, renderer)
   2015                 offsets = np.column_stack([xs, ys])
   2016 
-> 2017         self.update_scalarmappable()
   2018 
   2019         if not transform.is_affine:

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/collections.py in update_scalarmappable(self)
    761             return
    762         if self._is_filled:
--> 763             self._facecolors = self.to_rgba(self._A, self._alpha)
    764         elif self._is_stroked:
    765             self._edgecolors = self.to_rgba(self._A, self._alpha)

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/cm.py in to_rgba(self, x, alpha, bytes, norm)
    287         x = ma.asarray(x)
    288         if norm:
--> 289             x = self.norm(x)
    290         rgba = self.cmap(x, alpha=alpha, bytes=bytes)
    291         return rgba

~/.conda/envs/it4dnn/lib/python3.6/site-packages/matplotlib/colors.py in __call__(self, value, clip)
   1094             raise ValueError("minvalue must be less than or equal to maxvalue")
   1095         elif vmin <= 0:
-> 1096             raise ValueError("values must all be positive")
   1097         elif vmin == vmax:
   1098             result.fill(0)

ValueError: values must all be positive

<Figure size 432x288 with 2 Axes>

plot_groups = ['dataset', 'n_samples', 'd_dimensions', 'dataset', ]

subres = results_tstudent.groupby(plot_groups)

np.linspace(1, 100, 5)

array([  1.  ,  25.75,  50.5 ,  75.25, 100.  ])

fixed_vars.keys()

dict_keys(['d_dimensions', 'n_samples', 'dataset', 'scorer'])

t.groupby(['dataset', 'd_dimensions', 'scorer', 'nu']).mean()

				trial	n_samples	std	gamma	gamma_median	gamma_silv	gamma_scott	gamma_belkin	value
dataset	d_dimensions	scorer	nu
tstudent	2	ctka	1.0	3	50	NaN	0.696469	3.637672	0.521001	0.521001	1.414238	0.783332
			2.0	3	50	NaN	3.411414	2.371588	0.521001	0.521001	1.007945	0.659446
			3.0	3	50	NaN	7.953236	2.072371	0.521001	0.521001	0.919839	0.665852
			4.0	3	50	NaN	8.503696	1.937548	0.521001	0.521001	0.823425	0.636789
			5.0	3	50	NaN	9.013576	1.871554	0.521001	0.521001	0.817610	0.630266
			10.0	3	50	NaN	12.641237	1.761699	0.521001	0.521001	0.792941	0.700331
			15.0	3	50	NaN	13.868945	1.729998	0.521001	0.521001	0.781636	0.720690
			20.0	3	50	NaN	14.480582	1.708761	0.521001	0.521001	0.776870	0.728609
			30.0	3	50	NaN	15.092759	1.687802	0.521001	0.521001	0.772400	0.736512
		hsic	1.0	3	50	NaN	0.311456	3.637672	0.521001	0.521001	1.414238	0.021224
			2.0	3	50	NaN	4.483172	2.371588	0.521001	0.521001	1.007945	0.018766
			3.0	3	50	NaN	7.953236	2.072371	0.521001	0.521001	0.919839	0.018821
			4.0	3	50	NaN	8.503696	1.937548	0.521001	0.521001	0.823425	0.018640
			5.0	3	50	NaN	6.739547	1.871554	0.521001	0.521001	0.817610	0.018885
			10.0	3	50	NaN	12.641237	1.761699	0.521001	0.521001	0.792941	0.018856
			15.0	3	50	NaN	13.868945	1.729998	0.521001	0.521001	0.781636	0.018930
			20.0	3	50	NaN	14.480582	1.708761	0.521001	0.521001	0.776870	0.018957
			30.0	3	50	NaN	15.092759	1.687802	0.521001	0.521001	0.772400	0.018982
		tka	1.0	3	50	NaN	0.000166	3.637672	0.521001	0.521001	1.414238	0.999635
			2.0	3	50	NaN	0.000448	2.371588	0.521001	0.521001	1.007945	0.999753
			3.0	3	50	NaN	0.000795	2.072371	0.521001	0.521001	0.919839	0.999907
			4.0	3	50	NaN	0.000850	1.937548	0.521001	0.521001	0.823425	0.999460
			5.0	3	50	NaN	0.000901	1.871554	0.521001	0.521001	0.817610	0.999566
			10.0	3	50	NaN	0.001264	1.761699	0.521001	0.521001	0.792941	0.999915
			15.0	3	50	NaN	0.001387	1.729998	0.521001	0.521001	0.781636	0.999941
			20.0	3	50	NaN	0.001448	1.708761	0.521001	0.521001	0.776870	0.999949
			30.0	3	50	NaN	0.001509	1.687802	0.521001	0.521001	0.772400	0.999956

t.groupby(['dataset', 'd_dimensions', 'scorer', 'nu']).std()

				trial	n_samples	std	gamma	gamma_median	gamma_silv	gamma_scott	gamma_belkin	value
dataset	d_dimensions	scorer	nu
tstudent	2	ctka	1.0	1.581139	0.0	NaN	0.961500	0.782348	0.0	0.0	0.371900	0.166620
			2.0	1.581139	0.0	NaN	3.214027	0.304070	0.0	0.0	0.165151	0.050112
			3.0	1.581139	0.0	NaN	1.950137	0.211945	0.0	0.0	0.140706	0.072745
			4.0	1.581139	0.0	NaN	2.417514	0.172598	0.0	0.0	0.097211	0.046597
			5.0	1.581139	0.0	NaN	2.490371	0.178211	0.0	0.0	0.096458	0.041736
			10.0	1.581139	0.0	NaN	2.329043	0.139662	0.0	0.0	0.081018	0.044380
			15.0	1.581139	0.0	NaN	2.218147	0.119495	0.0	0.0	0.072778	0.042949
			20.0	1.581139	0.0	NaN	2.141577	0.111909	0.0	0.0	0.062929	0.041649
			30.0	1.581139	0.0	NaN	2.040238	0.106456	0.0	0.0	0.056623	0.038702
		hsic	1.0	1.581139	0.0	NaN	0.259527	0.782348	0.0	0.0	0.371900	0.004151
			2.0	1.581139	0.0	NaN	1.872368	0.304070	0.0	0.0	0.165151	0.000259
			3.0	1.581139	0.0	NaN	1.950137	0.211945	0.0	0.0	0.140706	0.000445
			4.0	1.581139	0.0	NaN	2.417514	0.172598	0.0	0.0	0.097211	0.000505
			5.0	1.581139	0.0	NaN	2.648875	0.178211	0.0	0.0	0.096458	0.000795
			10.0	1.581139	0.0	NaN	2.329043	0.139662	0.0	0.0	0.081018	0.000337
			15.0	1.581139	0.0	NaN	2.218147	0.119495	0.0	0.0	0.072778	0.000325
			20.0	1.581139	0.0	NaN	2.141577	0.111909	0.0	0.0	0.062929	0.000315
			30.0	1.581139	0.0	NaN	2.040238	0.106456	0.0	0.0	0.056623	0.000295
		tka	1.0	1.581139	0.0	NaN	0.000181	0.782348	0.0	0.0	0.371900	0.000596
			2.0	1.581139	0.0	NaN	0.000187	0.304070	0.0	0.0	0.165151	0.000179
			3.0	1.581139	0.0	NaN	0.000195	0.211945	0.0	0.0	0.140706	0.000063
			4.0	1.581139	0.0	NaN	0.000242	0.172598	0.0	0.0	0.097211	0.000904
			5.0	1.581139	0.0	NaN	0.000249	0.178211	0.0	0.0	0.096458	0.000300
			10.0	1.581139	0.0	NaN	0.000233	0.139662	0.0	0.0	0.081018	0.000033
			15.0	1.581139	0.0	NaN	0.000222	0.119495	0.0	0.0	0.072778	0.000017
			20.0	1.581139	0.0	NaN	0.000214	0.111909	0.0	0.0	0.062929	0.000012
			30.0	1.581139	0.0	NaN	0.000204	0.106456	0.0	0.0	0.056623	0.000009