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Capability index

Every public name in spectraldiffx (121 of them), each listed once and grouped as the API reference groups it, with the first sentence of its docstring; then the public API of gaussx, which spectraldiffx builds on. Search this page before writing a helper: if what you need is here, compose it; if it is almost here, extend it where it lives. Regenerate with make capabilities after changing a public API (tests/test_capabilities.py checks it is current).

spectraldiffx

Fourier: Spectral Transforms (docs/api/fourier/transforms.md)

1-D Transforms

Name Kind What it does
dct function Discrete Cosine Transform of a 1-D vector.
dst function Discrete Sine Transform of a 1-D vector.
idct function Inverse Discrete Cosine Transform of a 1-D vector.
idst function Inverse Discrete Sine Transform of a 1-D vector.

N-D Transforms

Name Kind What it does
dctn function N-dimensional DCT: apply DCT sequentially along each axis.
dstn function N-dimensional DST: apply DST sequentially along each axis.
idctn function N-dimensional inverse DCT: apply IDCT sequentially along each axis.
idstn function N-dimensional inverse DST: apply IDST sequentially along each axis.

Fourier: Eigenvalue Helpers (docs/api/fourier/eigenvalues.md)

FD2 Eigenvalues (Finite-Difference)

Name Kind What it does
dst1_eigenvalues function 1-D Laplacian eigenvalues for the DST-I basis (homogeneous Dirichlet BCs).
dst2_eigenvalues function 1-D Laplacian eigenvalues for the DST-II basis (Dirichlet BCs, staggered grid).
dct1_eigenvalues function 1-D Laplacian eigenvalues for the DCT-I basis (Neumann BCs, regular grid).
dct2_eigenvalues function 1-D Laplacian eigenvalues for the DCT-II basis (homogeneous Neumann BCs).
fft_eigenvalues function 1-D Laplacian eigenvalues for the FFT basis (periodic BCs).
dst3_eigenvalues function 1-D Laplacian eigenvalues for Dirichlet-left + Neumann-right on a regular grid.
dct3_eigenvalues function 1-D Laplacian eigenvalues for Neumann-left + Dirichlet-right on a regular grid.
dst4_eigenvalues function 1-D Laplacian eigenvalues for Dirichlet-left + Neumann-right on a staggered grid.
dct4_eigenvalues function 1-D Laplacian eigenvalues for Neumann-left + Dirichlet-right on a staggered grid.

PS Eigenvalues (Pseudo-Spectral)

Name Kind What it does
dst1_eigenvalues_ps function PS eigenvalues for DST-I (Dirichlet BCs, regular grid).
dst2_eigenvalues_ps function PS eigenvalues for DST-II (Dirichlet BCs, staggered grid).
dct1_eigenvalues_ps function PS eigenvalues for DCT-I (Neumann BCs, regular grid).
dct2_eigenvalues_ps function PS eigenvalues for DCT-II (Neumann BCs, staggered grid).
fft_eigenvalues_ps function PS eigenvalues for the FFT basis (periodic BCs).
dst3_eigenvalues_ps function PS eigenvalues for Dirichlet-left + Neumann-right on a regular grid.
dct3_eigenvalues_ps function PS eigenvalues for Neumann-left + Dirichlet-right on a regular grid.
dst4_eigenvalues_ps function PS eigenvalues for Dirichlet-left + Neumann-right on a staggered grid.
dct4_eigenvalues_ps function PS eigenvalues for Neumann-left + Dirichlet-right on a staggered grid.

Fourier: Fourier Grids (docs/api/fourier/grids.md)

Name Kind What it does
FourierGrid1D class Fourier grid setup for periodic domain.
FourierGrid2D class 2D Fourier grid for doubly periodic domain.
FourierGrid3D class 3D Fourier grid for triply periodic domain.

Fourier: Spectral Derivative Operators (docs/api/fourier/operators.md)

Name Kind What it does
SpectralDerivative1D class 1D Spectral derivative operator using the Fast Fourier Transform (FFT).
SpectralDerivative2D class 2D Spectral derivative operators for doubly periodic rectangular domains.
SpectralDerivative3D class 3D Spectral derivative operators for triply periodic domains.

Fourier: Spectral Filters (docs/api/fourier/filters.md)

Name Kind What it does
SpectralFilter1D class 1D Spectral filter for smoothing and numerical stabilization.
SpectralFilter2D class 2D Spectral filter for doubly periodic domains.
SpectralFilter3D class 3D Spectral filter for triply periodic domains.

Fourier: Spectral Elliptic Solvers (docs/api/fourier/solvers.md)

Layer 0 — Pure Functions

Name Kind What it does
solve_helmholtz_fft_1d function Solve (∇² − λ)ψ = f in 1-D with periodic BCs using the FFT.
solve_poisson_fft_1d function Solve ∇²ψ = f in 1-D with periodic BCs using FFT.
solve_helmholtz_fft function Solve (∇² − λ)ψ = f with periodic BCs using the 2-D FFT.
solve_poisson_fft function Solve ∇²ψ = f with periodic BCs using the 2-D FFT.
solve_helmholtz_fft_3d function Solve (∇² − λ)ψ = f with periodic BCs using the 3-D FFT.
solve_poisson_fft_3d function Solve ∇²ψ = f with periodic BCs using the 3-D FFT.
solve_helmholtz_dst1_1d function Solve (∇² − λ)ψ = f in 1-D with Dirichlet BCs on a regular grid (DST-I).
solve_poisson_dst1_1d function Solve ∇²ψ = f in 1-D with Dirichlet BCs on a regular grid (DST-I).
solve_helmholtz_dst function Solve (∇² − λ)ψ = f with homogeneous Dirichlet BCs using DST-I.
solve_poisson_dst function Solve ∇²ψ = f with homogeneous Dirichlet BCs using DST-I.
solve_helmholtz_dst1 function Solve (∇² − λ)ψ = f with homogeneous Dirichlet BCs using DST-I.
solve_poisson_dst1 function Solve ∇²ψ = f with homogeneous Dirichlet BCs using DST-I.
solve_helmholtz_dst1_3d function Solve (∇² − λ)ψ = f with Dirichlet BCs on a regular 3-D grid (DST-I).
solve_poisson_dst1_3d function Solve ∇²ψ = f with Dirichlet BCs on a regular 3-D grid (DST-I).
solve_helmholtz_dst2_1d function Solve (∇² − λ)ψ = f in 1-D with Dirichlet BCs on a staggered grid (DST-II).
solve_poisson_dst2_1d function Solve ∇²ψ = f in 1-D with Dirichlet BCs on a staggered grid (DST-II).
solve_helmholtz_dst2 function Solve (∇² − λ)ψ = f with Dirichlet BCs on a staggered grid (DST-II).
solve_poisson_dst2 function Solve ∇²ψ = f with Dirichlet BCs on a staggered grid (DST-II).
solve_helmholtz_dst2_3d function Solve (∇² − λ)ψ = f with Dirichlet BCs on a staggered 3-D grid (DST-II).
solve_poisson_dst2_3d function Solve ∇²ψ = f with Dirichlet BCs on a staggered 3-D grid (DST-II).
solve_helmholtz_dct1_1d function Solve (∇² − λ)ψ = f in 1-D with Neumann BCs on a regular grid (DCT-I).
solve_poisson_dct1_1d function Solve ∇²ψ = f in 1-D with Neumann BCs on a regular grid (DCT-I).
solve_helmholtz_dct1 function Solve (∇² − λ)ψ = f with Neumann BCs on a regular grid (DCT-I).
solve_poisson_dct1 function Solve ∇²ψ = f with Neumann BCs on a regular grid (DCT-I).
solve_helmholtz_dct1_3d function Solve (∇² − λ)ψ = f with Neumann BCs on a regular 3-D grid (DCT-I).
solve_poisson_dct1_3d function Solve ∇²ψ = f with Neumann BCs on a regular 3-D grid (DCT-I).
solve_helmholtz_dct2_1d function Solve (∇² − λ)ψ = f in 1-D with Neumann BCs on a staggered grid (DCT-II).
solve_poisson_dct2_1d function Solve ∇²ψ = f in 1-D with Neumann BCs on a staggered grid (DCT-II).
solve_helmholtz_dct function Solve (∇² − λ)ψ = f with homogeneous Neumann BCs using DCT-II.
solve_poisson_dct function Solve ∇²ψ = f with homogeneous Neumann BCs using DCT-II.
solve_helmholtz_dct2 function Solve (∇² − λ)ψ = f with homogeneous Neumann BCs using DCT-II.
solve_poisson_dct2 function Solve ∇²ψ = f with homogeneous Neumann BCs using DCT-II.
solve_helmholtz_dct2_3d function Solve (∇² − λ)ψ = f with Neumann BCs on a staggered 3-D grid (DCT-II).
solve_poisson_dct2_3d function Solve ∇²ψ = f with Neumann BCs on a staggered 3-D grid (DCT-II).
BoundaryCondition type alias Type alias: 'periodic', 'dirichlet', 'dirichlet_stag', 'neumann', 'neumann_stag', or one of 4 supported (left, right) pairs.
solve_helmholtz_2d function Solve (nabla^2 - lambda)psi = f in 2-D with per-axis boundary conditions.
solve_poisson_2d function Solve nabla^2 psi = f in 2-D with per-axis boundary conditions.
solve_helmholtz_3d function Solve (nabla^2 - lambda)psi = f in 3-D with per-axis boundary conditions.
solve_poisson_3d function Solve nabla^2 psi = f in 3-D with per-axis boundary conditions.
modify_rhs_1d function Apply boundary source terms for inhomogeneous BCs to a 1-D RHS.
modify_rhs_2d function Apply boundary source terms for inhomogeneous BCs to a 2-D RHS.
modify_rhs_3d function Apply boundary source terms for inhomogeneous BCs to a 3-D RHS.

Layer 1 — Module Classes

Name Kind What it does
SpectralHelmholtzSolver1D class 1D Helmholtz/Poisson solver with periodic BCs using FFT.
SpectralHelmholtzSolver2D class 2D Helmholtz/Poisson solver with periodic BCs using FFT.
SpectralHelmholtzSolver3D class 3D Helmholtz/Poisson solver with periodic BCs using FFT.
DirichletHelmholtzSolver2D class 2D Helmholtz/Poisson/Laplace solver with homogeneous Dirichlet BCs.
StaggeredDirichletHelmholtzSolver2D class 2D Helmholtz/Poisson solver with Dirichlet BCs on a staggered grid.
NeumannHelmholtzSolver2D class 2D Helmholtz/Poisson/Laplace solver with homogeneous Neumann BCs.
RegularNeumannHelmholtzSolver2D class 2D Helmholtz/Poisson solver with Neumann BCs on a regular grid.
MixedBCHelmholtzSolver2D class 2D Helmholtz/Poisson solver with per-axis boundary conditions.
MixedBCHelmholtzSolver3D class 3D Helmholtz/Poisson solver with per-axis boundary conditions.

Fourier: Capacitance Solver (docs/api/fourier/capacitance.md)

Name Kind What it does
build_capacitance_solver function Pre-compute the capacitance factorisation and return a solver.
CapacitanceSolver class Spectral Poisson/Helmholtz solver for masked irregular domains.

Chebyshev: Chebyshev Grids (docs/api/chebyshev/grids.md)

Name Kind What it does
ChebyshevGrid1D class 1D Chebyshev grid on the domain [-L, L].
ChebyshevGrid2D class 2D Chebyshev grid on [-Lx, Lx] × [-Ly, Ly].
ChebyshevGrid3D class 3D Chebyshev grid on [-Lz, Lz] × [-Ly, Ly] × [-Lx, Lx].

Chebyshev: Chebyshev Derivative Operators (docs/api/chebyshev/operators.md)

Name Kind What it does
ChebyshevDerivative1D class 1D Chebyshev derivative operator using the precomputed differentiation matrix.
ChebyshevDerivative2D class 2D Chebyshev derivative operators on [−Lx, Lx] × [−Ly, Ly].
ChebyshevDerivative3D class 3D Chebyshev derivative operators on [−Lz, Lz] × [−Ly, Ly] × [−Lx, Lx].

Chebyshev: Chebyshev Transforms, Calculus & Quadrature (docs/api/chebyshev/transforms.md)

Transforms

Name Kind What it does
ChebyshevTransform1D class Forward/inverse 1D Chebyshev transform.
ChebyshevTransform2D class Forward/inverse 2D Chebyshev transform (tensor product of 1D).
cheb_dealias_product function Compute the dealiased pointwise product a·b on a Chebyshev grid.

Coefficient-space calculus

Name Kind What it does
chebyshev_derivative_coeffs function Differentiate a Chebyshev series in coefficient space (last axis).
chebyshev_antiderivative_coeffs function Indefinite integral of a Chebyshev series, vanishing at x = −L.
chebyshev_integral_coeffs function Definite integral ∫_{−L}^{L} u(x) dx from Chebyshev coefficients.

Clenshaw–Curtis quadrature

Name Kind What it does
clenshaw_curtis_weights function Clenshaw–Curtis quadrature weights on Gauss–Lobatto nodes of [−L, L].
clenshaw_curtis_integrate_1d function Integrate a 1D nodal field over [−L, L] using Clenshaw–Curtis.
clenshaw_curtis_integrate_2d function Integrate a 2D nodal field over [−Lx, Lx] × [−Ly, Ly].

Chebyshev: Chebyshev Filters (docs/api/chebyshev/filters.md)

Name Kind What it does
ChebyshevFilter1D class 1D Chebyshev spectral filter for smoothing and numerical stabilisation.
ChebyshevFilter2D class 2D Chebyshev spectral filter on [−Lx, Lx] × [−Ly, Ly].

Chebyshev: Chebyshev Helmholtz Solvers (docs/api/chebyshev/solvers.md)

Name Kind What it does
ChebyshevHelmholtzSolver1D class 1D Chebyshev-collocation Helmholtz/Poisson solver with Dirichlet or Neumann BCs.
ChebyshevPoissonSolver1D class 1D Chebyshev Poisson solver: d²u/dx² = f on [−L, L].
ChebyshevHelmholtzSolver2D class 2D Chebyshev-collocation Helmholtz/Poisson solver with Dirichlet BCs.
ChebyshevPoissonSolver2D class 2D Chebyshev Poisson solver: ∇²u = f with Dirichlet BCs.

Spherical: Spherical Grids (docs/api/spherical/grids.md)

Name Kind What it does
SphericalGrid1D class Gauss-Legendre grid for the latitude (colatitude) direction.
SphericalGrid2D class Full sphere latitude-longitude pseudo-spectral grid.

Spherical: Spherical Derivative Operators (docs/api/spherical/operators.md)

Name Kind What it does
SphericalDerivative1D class 1D spectral derivative operator on Gauss-Legendre latitude grid.
SphericalDerivative2D class 2D pseudo-spectral derivative operators on the sphere.

Spherical: Spherical Filters (docs/api/spherical/filters.md)

Name Kind What it does
SphericalFilter1D class 1D spectral filter on the Gauss–Legendre latitude grid.
SphericalFilter2D class 2D spectral filter on the full sphere lat-lon grid.

Spherical: Spherical Harmonic Transform (docs/api/spherical/harmonics.md)

Name Kind What it does
SphericalHarmonicTransform class Full 2D Spherical Harmonic Transform (SHT).

Spherical: Spherical Harmonic Solvers (docs/api/spherical/solvers.md)

Name Kind What it does
SphericalPoissonSolver class Spectral Poisson solver on the sphere: ∇²φ = f.
SphericalHelmholtzSolver class Spectral Helmholtz solver on the sphere: (∇² − α) φ = f.

Geophysical inversions

Name Kind What it does
SphericalVorticityInversionSolver class Vorticity-inversion solver on the sphere.
SphericalDivergenceInversionSolver class Divergence-inversion solver on the sphere.
SphericalHelmholtzDecomposition class Helmholtz decomposition of a horizontal vector field on the sphere.

Listed at gaussx 0.1.0.

Upstream: gaussx

Structured linear algebra. spectraldiffx uses it for the masked-domain capacitance solver (DiagonalisedOperator, circulant_from_symbol, MaskedOperator, grid_coupling_indices, solve) and the Chebyshev Helmholtz solvers (EigenFactorization, kronecker_sum_solve). A new solve, factorisation or Woodbury / capacitance correction comes from here, not from a hand-written jnp.linalg call.

gaussx

Name Kind What it does
AbstractIntegrator class Protocol for Gaussian integral approximation.
AbstractLikelihood class Base class for likelihood functions with optional analytical ELL.
AbstractLogdetStrategy class Protocol for log-determinant strategies.
AbstractPreconditioner class Protocol for preconditioners producing an approximate inverse.
AbstractSolveStrategy class Protocol for linear solve strategies.
AbstractSolverStrategy class Protocol for solver strategies that pair solve + logdet.
AnalyticalPsiStatistics class Protocol for kernels with closed-form Ψ statistics.
AssumedDensityFilter class KL-optimal Gaussian projection via moment matching.
AutoSolver class Automatic solver selection based on operator type and size.
BBMMSolver class Black-Box Matrix-Matrix solver (Gardner et al. 2018).
BernoulliLikelihood class Bernoulli likelihood with logit link.
BlockDiag class Block diagonal operator diag(A₁, A₂, …, Aₖ).
BlockTriDiag class Symmetric block-tridiagonal operator.
CGSolver class Iterative CG solver with stochastic log-determinant.
CapacitanceSolver class Solve a base system subject to homogeneous point constraints.
Circulant function (Block-)circulant operator from its first column.
ComposedSolver class Mix-and-match solve and logdet from different strategies.
ConstantSDE class State-space representation of a constant kernel.
CosineSDE class State-space representation of the cosine kernel.
CubatureIntegrator class Third-order spherical-radial cubature.
DAREResult class Result of DARE solver.
DenseFallbackWarning class Warning emitted when a structured primitive materialises an operator.
DenseLogdet class Dense log-determinant via gaussx structural dispatch.
DenseSolver class Dense solver strategy using gaussx structural dispatch.
DiagonalisedOperator class Linear operator A x = V⁻¹(Λ ⊙ V x) given by a transform pair.
EigenFactorization class Precomputed eigendecomposition A = V diag(λ) V⁻¹ of a square matrix.
EigenProPreconditioner class Spectral correction state for EigenPro kernel SGD.
EmissionModel class Observation (emission) model wrapping a linear observation matrix.
FalkonPreconditioner class The two upper-triangular Cholesky factors of the Falkon preconditioner.
FifthOrderCubatureIntegrator class Fifth-order fully symmetric cubature (McNamee & Stenger).
FilterState class Output of kalman_filter.
GaussHermiteIntegrator class Gauss-Hermite quadrature integrator.
GaussianExpFam class Gaussian in natural (exponential family) parameters.
GaussianLikelihood class Gaussian likelihood log N(y \| f, noise_var * I).
GaussianSites class Time-varying Gaussian likelihood sites in natural parameterization.
GaussianState class Gaussian distribution as (mean, covariance operator) pair.
HeteroscedasticGaussianLikelihood class Heteroscedastic Gaussian likelihood with input-dependent noise.
ImplicitCrossKernelOperator class Matrix-free rectangular kernel operator K(X, Z) \cdot v.
ImplicitKernelOperator class Matrix-free kernel operator: (K + sigma^2 I) v via sequential scan.
IndefiniteSLQLogdet class Stochastic log\|det(A)\| for symmetric (possibly indefinite) operators.
InfiniteHorizonState class Output of infinite_horizon_filter.
IntegratedWienerSDE class State-space representation of an integrated Wiener process.
InterpolatedOperator class Structured Kernel Interpolation: K \approx W K_{uu} W^T.
JacobiPreconditioner class Diagonal preconditioner M^{-1} = diag(1 / diag(A)).
KernelOperator class Kernel matrix operator with efficient first-order autodiff.
Kronecker class Kronecker product operator A₁ ⊗ A₂ ⊗ … ⊗ Aₖ.
KroneckerSum class Kronecker sum A \oplus B = A \otimes I_b + I_a \otimes B.
KroneckerSumSqrt class Symmetric square root of A \oplus B via per-factor eigenvectors.
LOOResult class Result of leave-one-out cross-validation.
LOVECache class Cached Lanczos factorization for fast predictive variance.
LSMRSolver class LSMR iterative least-squares solver (Fong & Saunders 2011).
LowRankUpdate class Low-rank update operator L + U diag(d) Vᵀ.
LowerBlockTriDiag class Lower triangular block-bidiagonal Cholesky factor.
MINRESSolver class MINRES solver for symmetric (possibly indefinite) systems.
MaskedOperator class Row/column-masked view of a base operator.
MaternSDE class State-space representation of the Matern kernel.
MomentMatchResult class Tilted log-normaliser and its derivatives w.r.t. the cavity mean.
MonteCarloIntegrator class Monte Carlo moment matching: sample, propagate, compute moments.
NystromPreconditioner class Low-rank approximate inverse from randomized operator probing.
OperatorPreconditioner class Use an externally supplied approximate inverse as a preconditioner.
PartialCholeskyPreconditioner class Preconditioner from a pivoted partial Cholesky factor.
PeriodicSDE class State-space representation of the periodic (MacKay) kernel.
PoissonLikelihood class Poisson likelihood with log link.
PreconditionedCGSolver class CG solver with pivoted partial Cholesky preconditioner.
PredictionCache class Cached training solve for amortized predictions.
ProductOperator function Lazy matmul (A B) v = A (B v).
ProductSDE class Product of two SDE kernels via Kronecker composition.
PropagationResult class Output of uncertainty propagation through a nonlinear function.
QuasiPeriodicSDE class Quasi-periodic kernel: product of Matern and Periodic SDE.
RootDecomposition class Tall factor R with R Rᵀ ≈ A semantics.
SDEKernel class Abstract base class for state-space kernel representations.
SDEParams class Continuous-time SDE parameters for a linear SDE.
SLQLogdet class Stochastic log-determinant via Lanczos quadrature (SLQ).
SLRResult class Linear-Gaussian surrogate produced by statistical linear regression.
SVDLowRankUpdate class Deprecated subclass of LowRankUpdate with orthonormal=True.
ScaledOperator function Lazy scalar multiply (c A) v = c (A v).
SoftmaxLikelihood class Softmax (categorical) likelihood for multi-class classification.
StudentTLikelihood class Student-t likelihood for robust regression.
SumKronecker class Deprecated alias for SumOfKroneckers.
SumKroneckerSqrt class Lazy Lanczos square-root operator for SumOfKroneckers covariances.
SumOfKroneckers class Sum of Kronecker products Σ_k A_k \otimes B_k.
SumOperator function Lazy sum (A + B + …) v = A v + B v + ….
SumSDE class Sum of SDE kernels via block-diagonal composition.
TaylorIntegrator class 1st or 2nd order Taylor expansion for uncertainty propagation.
Toeplitz class Symmetric Toeplitz matrix from its first column.
ToeplitzCholesky class Circulant-embedding sample factor for a symmetric positive Toeplitz matrix.
UDLDecomposition class Banded factorisation \(\Lambda = U \tilde{D} U^{\top}\) of a BlockTriDiag.
UnscentedIntegrator class Unscented transform: deterministic sigma points.
UpperBlockTriDiag class Upper triangular block-bidiagonal (transpose of LowerBlockTriDiag).
add_jitter function Add diagonal jitter for numerical stability: A + eps * I.
as_diagonalised function Express operator as one DiagonalisedOperator, if possible.
as_linear_operator function Wrap a raw matvec callable as a tagged lineax operator.
base_conditional function Gaussian conditional distribution via Schur complement.
batched_kernel_matvec function Compute K(X, Z) @ v in memory-efficient batches.
batched_kernel_rmatvec function Compute K(X, Z)^T @ u in memory-efficient batches.
block_diagonal_tag constant block_diagonal_tag
block_tridiagonal_tag constant block_tridiagonal_tag
blr_diag_update function Diagonal natural parameter BLR update step.
blr_full_update function Full-rank natural parameter BLR update step.
build_prediction_cache function Solve A alpha = y and cache the result.
cavity_distribution function Compute EP cavity distribution by removing a site.
cavity_from_marginal function Compute cavity distribution by removing a site from the marginal.
center_kernel function Center a kernel matrix: H K H.
centering_operator function Centering matrix H = I - (1/n) \mathbf{1}\mathbf{1}^T.
cholesky function Compute Cholesky factor L such that A = L L^T.
cholesky_logdet function Compute log|A| from Cholesky factor L where A = L Lᵀ.
circulant_from_symbol function (Block-)circulant operator from its DFT symbol.
collapsed_elbo function Collapsed ELBO (Titsias bound) for sparse GP regression.
compute_psi_statistics function Compute Ψ statistics, dispatching to analytical or numerical.
conditional function Compute p(x_A \| x_B = b) from a joint Gaussian p(x_A, x_B).
conditional_interpolate function Interpolated marginal at time t given posteriors at t^- and t^+.
conditional_variance function Predictive variance: Schur complement diagonal plus optional variational correction.
cost_expectation function Compute E[Cost(f(x), target)] where x ~ N(mu, Sigma).
cov_transform function Covariance propagation through a linear map: J @ Sigma @ J^T.
create_grid function Create a regular grid from per-dimension sizes and bounds.
cubature_points function Spherical-radial cubature points and weights.
cubic_interpolation_weights function Compute cubic interpolation indices and weights for SKI.
cvi_update_sites function Natural gradient update for CVI sites.
damped_natural_update function Damped update in natural parameter space.
dare function Discrete Algebraic Riccati Equation solver.
diag function Extract the diagonal of an operator as a 1D array.
diag_conditional_variance function Diagonal of Schur complement: diag(K_XX - A K_ZX).
diag_inv function Compute the diagonal of the inverse of a linear operator.
diagonal_tag constant Re-exported from lineax.
discrepancy_step_size function Adaptive EKI tempering step: the data misfit controller.
discrete_lyapunov_solve function Solve the discrete Lyapunov equation P - G P G^T = Q.
discretise_mfd function Discretise a linear SDE by matrix-fraction decomposition.
discretise_mfd_sequence function Vectorised gaussx.discretise_mfd over a vector of time steps.
dist_kl_divergence function KL divergence KL(p \|\| q) between two multivariate normals.
eig function Compute eigenvalues and eigenvectors.
eigenpro_correction function Compute the EigenPro eigenspace correction for one SGD mini-batch.
eigenpro_preconditioner function Build an EigenPro spectral preconditioner from a kernel operator.
eigenpro_step_size function Return the EigenPro preconditioned step size for a batch size.
eigvals function Compute eigenvalues only.
eki_step function One ensemble Kalman inversion (EKI) update.
elbo function Evidence lower bound (ELBO).
enkf_analysis function Stochastic (perturbed-observation) ensemble Kalman analysis step.
ensemble_covariance function Empirical covariance from an ensemble as a low-rank operator.
ensemble_cross_covariance function Cross-covariance between two ensemble sets.
ensemble_kalman_gain function Kalman gain from an ensemble and its image in observation space.
ep_tilted_moments function Compute tilted distribution moments via Gauss-Hermite quadrature.
estimate_spectral_bounds function Estimate \((\lambda_{\min}, \lambda_{\max})\) of a symmetric operator.
etkf_transform function Ensemble Transform Kalman Filter (ETKF) analysis weights.
euclidean_distance function Pairwise Euclidean distances \|\|a_i - b_j\|\|.
expectation_to_meanvar function Convert expectation parameters to mean/variance (Cholesky).
expectation_to_natural function Convert expectation parameters to natural parameters.
expectations_to_ssm function Convert expectation parameters back to SSM marginals.
expected_log_likelihood function Unified expected log-likelihood with analytical dispatch.
falkon_preconditioner function Build the Falkon preconditioner from the inducing-point kernel matrix.
falkon_predict function Predict with Nyström KRR weights: \(f(x_*) = \sum_j \alpha_j\, k(x_*, z_j)\).
falkon_solve function Nyström kernel ridge regression weights by Falkon's preconditioned CG.
fifth_order_cubature_points function Fifth-order fully symmetric cubature points and weights.
fisher_info function Fisher information matrix F(eta) = nabla^2 A(eta).
frobenius_norm function Compute the Frobenius norm \|\|A\|\|_F with structural dispatch.
gaspari_cohn function Gaspari-Cohn (1999) fifth-order compactly-supported taper.
gauss_hermite_points function Gauss-Hermite quadrature points and weights.
gauss_kl function KL divergence KL[q(u) \|\| p(u)] between Gaussian distributions.
gauss_newton_precision function Gauss-Newton precision matrix J^T J.
gaussian_entropy function Entropy of a multivariate normal N(mu, Sigma).
gaussian_expected_log_lik function Expected log-likelihood E_q[log N(y \| f, R)].
gaussian_log_prob function Multivariate normal log-probability.
ggn_diagonal function Generalized Gauss-Newton diagonal approximation.
gradient_expectation function Compute E[nabla f(x)] via Stein's lemma.
grid_coupling_indices function Flat indices of masked-out grid cells adjacent to the masked-in region.
grid_data function Expand a grid to the full Cartesian product of grid points.
haversine_distance function Pairwise great-circle (haversine) distances on a sphere.
hsic function Biased HSIC estimator.
hutchinson_hessian_diag function Stochastic Hessian diagonal via Hutchinson with Rademacher probes.
implicit_cross_kernel function Create a matrix-free rectangular cross-kernel operator.
infinite_horizon_filter function Infinite-horizon Kalman filter with fixed steady-state gain.
infinite_horizon_smoother function Infinite-horizon RTS smoother with fixed steady-state gain.
inflate_multiplicative function Multiplicative ensemble inflation about the mean.
inflate_rtpp function Relaxation to prior perturbations (RTPP; Zhang et al. 2004).
inflate_rtps function Relaxation to prior spread (RTPS; Whitaker & Hamill 2012).
inv function Return a lazy inverse operator A^{-1}.
inv_quad_logdet function Joint inverse-quadratic and log-determinant via shared BBMM CG.
is_block_diagonal function Check whether operator carries the block-diagonal tag.
is_block_tridiagonal function Check whether operator carries the block-tridiagonal tag.
is_diagonal function Re-exported from lineax.
is_kronecker function Check whether operator carries the Kronecker tag.
is_kronecker_sum function Check whether operator carries the Kronecker sum tag.
is_low_rank function Check whether operator carries the low-rank tag.
is_lower_triangular function Re-exported from lineax.
is_negative_semidefinite function Re-exported from lineax.
is_positive_semidefinite function Re-exported from lineax.
is_symmetric function Re-exported from lineax.
is_upper_triangular function Re-exported from lineax.
joseph_update function Numerically stable Joseph-form covariance update.
kalman_filter function Kalman filter forward pass via jax.lax.scan.
kalman_gain function Compute Kalman gain K = P @ H^T @ (H @ P @ H^T + R)^{-1}.
kernel_expectations function Compute kernel expectations Psi_0, Psi_1, Psi_2 for uncertain inputs.
kl_divergence function KL divergence KL(q \|\| p) via the Bregman-divergence form on natural parameters.
kl_standard_normal function KL divergence KL(N(m, S) \|\| N(0, I)).
kronecker_mll function Exact marginal log-likelihood for a Kronecker-structured GP.
kronecker_posterior_predictive function Posterior mean and variance for a Kronecker GP at test points.
kronecker_sum_sample function Sample from 𝒩(0, A ⊕ B) using per-factor eigendecompositions.
kronecker_sum_solve function Solve a shifted Kronecker-sum system in tensor (unvectorized) form.
kronecker_sum_tag constant kronecker_sum_tag
kronecker_tag constant kronecker_tag
leave_one_out_cv function LOO-CV via the bordered-system identity.
linear_solve function Solve A x = b through the unified front door.
localization_matrix function Pairwise Gaspari-Cohn taper rho(dist(a_i, b_j); c).
localized_kalman_gain function Ensemble Kalman gain with Hadamard (Schur-product) localization.
log_likelihood_expectation function Compute E[log p(y_{obs} \| f(x))] where x ~ N(mu, Sigma).
log_marginal_likelihood function GP log marginal likelihood.
log_partition function Log-partition function A(eta).
logdet function Compute log |det(A)| with structural dispatch.
love_cache function Precompute Lanczos factorization of K^{-1} for fast variance.
love_variance function Fast predictive variance using a LOVE cache.
low_rank_plus_diag function Construct diag(diag) + U diag(d) Vᵀ.
low_rank_plus_identity function Construct scale * I + U diag(d) Vᵀ.
low_rank_tag constant low_rank_tag
lower_triangular_tag constant Re-exported from lineax.
masked_moment_inputs function Make masked observation channels inert in a moment-matched update.
matheron_update function Posterior samples via Matheron's-rule correction.
mean_cov_to_natural function Convert mean/covariance to natural parameters (operator form).
mean_expectation function Compute E[f(x)] where x ~ N(mu, Sigma).
meanfield_kalman_filter function Mean-field Kalman filter over L = D // block_size state blocks.
meanfield_rts_smoother function Mean-field RTS smoother over L = D // block_size state blocks.
meanvar_to_expectation function Convert mean/variance (Cholesky) to expectation parameters.
meanvar_to_natural function Convert mean/variance (Cholesky) to natural parameters.
mmd_squared function Biased squared Maximum Mean Discrepancy.
moment_match function EP moment matching: tilted log-normaliser and its first two derivatives.
moment_transform function Moment triple of (x, fn(x)) for x Gaussian.
natural_to_expectation function Convert natural parameters to expectation parameters.
natural_to_mean_cov function Convert natural parameters to mean/covariance (operator form).
natural_to_meanvar function Convert natural parameters to mean/variance (Cholesky).
naturals_to_ssm function Convert natural parameters back to SSM parameters.
negative_semidefinite_tag constant Re-exported from lineax.
newton_update function Convert a Newton step to natural pseudo-likelihood parameters.
nonlinear_kalman_filter function Moment-matched nonlinear Kalman filter.
nonlinear_kalman_predict function One moment-matched predict step.
nonlinear_kalman_update function One moment-matched update step.
nonlinear_rts_smoother function Moment-matched nonlinear Rauch-Tung-Striebel smoother.
nonlinear_rts_step function One moment-matched RTS backward step.
nystrom_operator function Nystrom low-rank kernel approximation.
oilmm_back_project function Back-project latent GP predictions to the observation space.
oilmm_project function Project multi-output data to independent latent GPs via OILMM.
pairwise_marginals function Joint p(x_k, x_{k+1}) for each consecutive pair.
parallel_kalman_filter function Parallel Kalman filter via jax.lax.associative_scan.
parallel_rts_smoother function Parallel RTS smoother via reverse jax.lax.associative_scan.
positive_semidefinite_tag constant Re-exported from lineax.
predict_mean function Predictive mean: mu* = K_*f @ alpha.
predict_variance function Predictive variance: sigma^2* = k_** - diag(K_*f K_y^{-1} K_f*).
process_noise_covariance function Compute process noise from stationary covariance.
project function Compute A_X = K_XZ @ K_ZZ^{-1} via Cholesky solve.
quadratic_form function Compute x^T A^{-1} x via a single solve.
rff_operator function Random Fourier Features kernel approximation.
riemannian_psd_correction function Riemannian gradient correction for PSD precision updates.
root_decomposition function Compute a tall factor R such that R Rᵀ ≈ A.
root_inv_decomposition function Compute a tall factor R⁻ such that R⁻ (R⁻)ᵀ ≈ A⁻¹.
rts_smoother function Rauch-Tung-Striebel backward smoother.
safe_cholesky function Cholesky decomposition with adaptive jitter for near-singular matrices.
sample_joint_conditional function Joint draws of a partitioned Gaussian, and conditional draws from them.
sample_mvn function Draw samples from \(\mathcal{N}(\mu, K)\), dispatching on \(K\)'s structure.
sandwich function Return A @ P @ A.T exploiting compatible operator structure.
schur_complement function Schur complement: K_XX - K_XZ @ K_ZZ^{-1} @ K_ZX.
sde_autocovariance function Compute the stationary autocovariance of an SDE kernel.
sigma_points function Unscented transform sigma points and weights.
site_mean_var_from_natural function Convert per-site natural parameters to mean/variance.
site_natural_from_tilted function Compute site natural parameters from tilted and cavity moments.
sites_to_precision function Convert Gaussian sites to a block-tridiagonal precision.
solve function Solve A x = b with structural dispatch.
solve_columns function Solve A X = B column-by-column via vmap.
solve_matrix function Solve A X = B with a single factorization on the matrix RHS.
solve_rows function Solve A x = bᵢ for each row bᵢ of a matrix via vmap.
solve_tridiagonal function Solve a tridiagonal system A x = d.
solve_tridiagonal_batched function Solve independent tridiagonal systems over leading batch dimensions.
spingp_log_likelihood function Log marginal likelihood via sparse inverse GP formulation.
spingp_posterior function Posterior mean and precision via SpInGP.
sqrt function Compute matrix square root S such that S @ S = A.
sqrt_inv_matmul function Compute \(A^{-1/2} b\) via contour-integral quadrature.
sqrt_matmul function Compute \(A^{1/2} b\) via contour-integral quadrature.
ssm_to_expectations function Convert SSM marginals to expectation parameters.
ssm_to_naturals function Convert SSM parameters to natural parameters.
stable_rbf_kernel function RBF (squared exponential) kernel with mixed-precision stability.
stable_squared_distances function Squared Euclidean distances with mixed-precision stability.
statistical_linear_regression function Moment-match a nonlinear conditional to a linear-Gaussian surrogate.
submatrix function Extract A[row_idx, col_idx] without forming the full matrix.
sufficient_stats function Compute sufficient statistics T(x) = [x, x x^T].
sumkronecker_sample function Sample from 𝒩(0, op) with matrix-free Lanczos square roots.
svd function Compute the singular value decomposition A = U diag(s) V^T.
svd_low_rank_plus_diag function Construct diag(diag) + U diag(S) Vᵀ from a truncated SVD.
svgp_variance_adjustment function Compute the SVGP variance adjustment operator.
symmetric_tag constant Re-exported from lineax.
symmetrize function Symmetrize the trailing two axes: 0.5 * (X + X^T).
tikhonov_augment function Observation augmentation for Tikhonov-regularised EKI (TEKI).
to_expectation function Convert natural to expectation parameters.
to_natural function Convert expectation to natural parameters.
toeplitz_sample function Sample from 𝒩(0, Toeplitz(column)) via FFT circulant embedding.
trace function Compute the trace of an operator.
trace_and_diag function Jointly estimate the trace and diagonal from one probe pass.
trace_correction function Trace term in Titsias collapsed ELBO.
trace_product function Trace of a matrix product: tr(A @ B) with structural dispatch.
tridiagonal_tag constant Re-exported from lineax.
udl_decomposition function Factorise a symmetric block-tridiagonal precision as \(U \tilde{D} U^{\top}\).
udl_from_ssm_params function Build the UDLDecomposition of a Gauss-Markov chain's precision.
udl_to_ssm_params function Read the equivalent Gauss-Markov chain off a UDLDecomposition.
uncertain_bgplvm_predict function Multi-output uncertain GP prediction for BGPLVM.
uncertain_gp_predict function Predictive mean and variance for GP with uncertain inputs.
uncertain_gp_predict_mc function Monte Carlo GP prediction with uncertain inputs.
uncertain_svgp_predict function Predictive mean and variance for SVGP with uncertain inputs.
uncertain_vgp_predict function Predictive mean and variance for dense VGP with uncertain inputs.
unit_diagonal_tag constant Re-exported from lineax.
unwhiten function Unwhiten variational mean: m = L @ m_tilde.
unwhiten_covariance function Unwhiten variational covariance: S = L S̃ Lᵀ.
upper_triangular_tag constant Re-exported from lineax.
variational_elbo_gaussian function Titsias collapsed ELBO for Gaussian likelihoods.
variational_elbo_mc function Monte Carlo ELBO for non-conjugate likelihoods.
whiten_covariance function Unwhiten variational covariance: S = L S̃ Lᵀ.
whitened_svgp_predict function Whitened SVGP prediction: mean and variance at test points.
woodbury_solve function Standalone Woodbury identity solve: (L + U diag(D) U^T)^{-1} b.