Twelve production units have no documentation page

[gabrielfrasantos]

Severity: low
Domain: docs
Status: VERIFIED — measured against a210d34 on 2026-08-10
Suggested labels: documentation

Summary

AGENTS.md requires a design-first doc/<domain>/<Name>.md per algorithm. Twelve
production units have none. A separate set of index/naming mismatches is listed below.

Measurement

$ for h in $(find numerical -name '*.hpp' -not -path '*/test*' -not -path '*/platform/*'); do \
      b=$(basename "$h" .hpp); \
      find doc -name "$b.md" | grep -q . || echo "$b ($h)"; \
  done

Units correctly covered by combined pages were then excluded manually:
DormandPrince45 → RungeKuttaIntegrators.md, L1/L2 → Regularization.md,
Windowing → window.md.

Genuinely undocumented

Unit	Header
Statistics	numerical/math/Statistics.hpp
Matrix	numerical/math/Matrix.hpp
Toeplitz	numerical/math/Toeplitz.hpp
Geometry3D	numerical/math/Geometry3D.hpp
RecursiveBuffer	numerical/math/RecursiveBuffer.hpp
Tolerance	numerical/math/Tolerance.hpp
ComplexNumber	numerical/math/ComplexNumber.hpp
QNumber	numerical/math/QNumber.hpp
Math / ConstexprMath	numerical/math/Math.hpp
KalmanFilterBase	numerical/filters/active/KalmanFilterBase.hpp
PidIncremental	numerical/controllers/implementations/PidIncremental.hpp
FastFourierTransformRadix2Impl	numerical/analysis/FastFourierTransformRadix2Impl.hpp

Interface-only headers (Solver, Estimator, ObjectiveFunction, OdeSystem, the controller
interfaces, CompilerOptimizations) are excluded — they arguably do not need algorithm pages, but a
policy decision would help.

Index and naming mismatches

• doc/filters/README.md still says
  "(Coming soon — FIR and IIR filter documentation)" although both pages exist.
• doc/controllers/Pid.md documents Pid, but the implementation is
  PidIncremental — no header matches the page name.
• doc/windowing/window.md is lowercase, unlike every other page.

Suggested fix

Add pages per doc/TEMPLATE.md, update the domain README.md tables, and
decide whether pure interfaces are exempt (then state that in AGENTS.md).