Module construction 

Structs

CanonicalPenalty

A canonicalized penalty with block-local root, ready for the solver.

EngineDims

Minimal engine layout descriptor that avoids domain-specific layout coupling.

KroneckerReparamResult

Result of Kronecker-factored reparameterization.

PenaltyMatrix

PenaltyNullSplit

The λ-invariant declared-null subspace of a penalty reparameterization, materialized in both coefficient frames (#2454).

ReparamInvariant

Lambda-independent reparameterization invariants derived from penalty structure.

ReparamResult

Result of the stable reparameterization algorithm from Wood (2011) Appendix B

Enums

PenaltyFrame

The coefficient frame a set of penalty roots is expressed in.

PenaltyRepresentation

Functions

canonicalize_penalty_spec

Canonicalize a single PenaltySpec into a CanonicalPenalty by computing the block-local eigendecomposition and extracting the root.

canonicalize_penalty_specs

Canonicalize a batch of penalty specs, dropping zero-rank penalties. Returns (active_penalties, active_nullspace_dims).

create_balanced_penalty_root_from_canonical

Creates a balanced penalty root from canonical penalties.

kronecker_logdet_and_derivatives

kronecker_product

Computes the Kronecker product A ⊗ B for penalty matrix construction. This is used to create tensor product penalties that enforce smoothness in multiple dimensions for interaction terms.

kronecker_reparameterization_engine

Kronecker-factored reparameterization for tensor-product penalties.

kronecker_reparameterization_engine_with_invariant

Kronecker-factored reparameterization reusing a precomputed λ-invariant structure (eigensystems, reparameterized marginals, shrinkage scale).

precompute_reparam_invariant_from_canonical

Precompute the lambda-invariant reparameterization structure from canonical penalties.

report_penalty_pair_redundancy

Measure and report how close each pair of penalties in the canonical bundle comes to being proportional.

stable_reparameterization_engine_canonical

Engine-facing stable reparameterization API using only (p, k).

stable_reparameterizationwith_invariant

trace_penalty_covariance_in_orthogonal_basis

trace_reduced_penalty_covariance