Add circular relaxed S3F prediction helpers

[FlorianPfaff]

Summary

Adds a narrow S1 x R2 relaxed S3F helper module for equal-width circular grids. The helper computes closed-form circular cell statistics and delegates prediction through the existing StateSpaceSubdivisionFilter.predict_linear(...) path, preserving the current baseline implementation.

Included pieces:

• src/pyrecest/filters/relaxed_s3f_circular.py
• tests/filters/test_relaxed_s3f_circular.py

Excluded from this PR intentionally: experiment runner scripts, generated plots, generated CSVs, and notes from the local pilot run.

Details

The new helper supports three variants for direct comparison:

• baseline: representative-cell displacement
• r1: cell-averaged displacement
• r1_r2: cell-averaged displacement plus grid-induced covariance inflation

The tests cover positive-semidefinite covariance inflation, closed-form statistics against dense deterministic quadrature, mass conservation through predict/update, and convergence of the relaxation terms under grid refinement.

Validation

PYTHONPATH=src python -m pytest tests/filters/test_relaxed_s3f_circular.py -q

Result: 4 passed.

[github-actions]

✅MegaLinter analysis: Success

Descriptor	Linter	Files	Fixed	Errors	Warnings	Elapsed time
✅ COPYPASTE	jscpd	yes		no	no	12.05s
✅ JSON	prettier	2	0	0	0	0.46s
✅ JSON	v8r	2		0	0	10.66s
✅ MARKDOWN	markdownlint	16	0	0	0	1.15s
✅ MARKDOWN	markdown-table-formatter	16	0	0	0	0.3s
✅ PYTHON	bandit	427		0	0	6.0s
✅ PYTHON	black	427	0	0	0	8.6s
✅ PYTHON	flake8	427		0	0	3.25s
✅ PYTHON	isort	427	2	0	0	0.79s
✅ PYTHON	mypy	427		0	0	5.28s
✅ PYTHON	pylint	427		0	0	125.26s
✅ PYTHON	ruff	427	2	0	0	0.08s
✅ REPOSITORY	checkov	yes		no	no	22.73s
✅ REPOSITORY	gitleaks	yes		no	no	7.9s
✅ REPOSITORY	git_diff	yes		no	no	0.06s
✅ REPOSITORY	secretlint	yes		no	no	6.91s
✅ REPOSITORY	syft	yes		no	no	3.09s
✅ REPOSITORY	trivy-sbom	yes		no	no	3.33s
✅ REPOSITORY	trufflehog	yes		no	no	19.37s
✅ YAML	prettier	5	0	0	0	0.48s
✅ YAML	v8r	5		0	0	12.99s
✅ YAML	yamllint	5		0	0	0.59s

See detailed reports in MegaLinter artifacts

Your project could benefit from a custom flavor, which would allow you to run only the linters you need, and thus improve runtime performances. (Skip this info by defining FLAVOR_SUGGESTIONS: false)

• Documentation: Custom Flavors
• Command: npx mega-linter-runner@9.4.0 --custom-flavor-setup --custom-flavor-linters PYTHON_PYLINT,PYTHON_BLACK,PYTHON_FLAKE8,PYTHON_ISORT,PYTHON_BANDIT,PYTHON_MYPY,PYTHON_RUFF,COPYPASTE_JSCPD,JSON_V8R,JSON_PRETTIER,MARKDOWN_MARKDOWNLINT,MARKDOWN_MARKDOWN_TABLE_FORMATTER,REPOSITORY_CHECKOV,REPOSITORY_GIT_DIFF,REPOSITORY_GITLEAKS,REPOSITORY_SECRETLINT,REPOSITORY_SYFT,REPOSITORY_TRIVY_SBOM,REPOSITORY_TRUFFLEHOG,YAML_PRETTIER,YAML_YAMLLINT,YAML_V8R

Show us your support by starring ⭐ the repository

[github-actions]

Test Results

    12 files      12 suites   4h 33m 21s ⏱️
 1 211 tests  1 211 ✅     0 💤 0 ❌
14 896 runs  11 364 ✅ 3 532 💤 0 ❌

Results for commit 3625c89.

♻️ This comment has been updated with latest results.