Category: literature · Severity: medium
Location: gpjax/state_space/kernels.py:174 — _to_sde_product_kernel``
Problem
The SDE registry rejects all ProductKernels (kernels.py:175-178), which blocks the canonical quasi-periodic kernel TruncatedPeriodic × Matérn (Solin & Särkkä 2014 §3) whose state dimension is only (2K+1)·d. Both factor SDEs already exist, and the module's own Mauna Loa example (examples/state_space_gps.py:99-100,149-154) documents the gap and substitutes a sum.
Recommendation
Add a product-SDE construction for the Periodic×stationary case (Kronecker of the factor state-space models); keep the explicit rejection only for genuinely unsupported products.
Filed from the 2026-07-02 GPJax codebase audit (medium tier). Companion spec for the high-severity items: plans/2026-07-02-audit-high-severity-remediation-design.md.
Category: literature · Severity: medium
Location:
gpjax/state_space/kernels.py:174 —_to_sde_product_kernel``Problem
The SDE registry rejects all
ProductKernels (kernels.py:175-178), which blocks the canonical quasi-periodic kernelTruncatedPeriodic × Matérn(Solin & Särkkä 2014 §3) whose state dimension is only (2K+1)·d. Both factor SDEs already exist, and the module's own Mauna Loa example (examples/state_space_gps.py:99-100,149-154) documents the gap and substitutes a sum.Recommendation
Add a product-SDE construction for the Periodic×stationary case (Kronecker of the factor state-space models); keep the explicit rejection only for genuinely unsupported products.
Filed from the 2026-07-02 GPJax codebase audit (medium tier). Companion spec for the high-severity items:
plans/2026-07-02-audit-high-severity-remediation-design.md.