[kgryte]

Resolves a part of #11352.

Description

What is the purpose of this pull request?

This pull request:

• migrates the test suite for stats/base/dists/cosine/logcdf from relative tolerance (EPS/delta/tol) assertions to ULP difference assertions using @stdlib/assert/is-almost-same-value.
• updates test/test.logcdf.js, test/test.factory.js, and test/test.native.js. No other files are changed.

The ULP bound was tightened agentically: starting from a high bound and lowering to the minimum integer which still passes over the full fixture set (positive_mean, negative_mean, large_variance; 1000 cases each, 3000 total per file).

Measured minimum ULP bounds:

File	Fixture	ULP
test/test.logcdf.js	positive_mean	513
test/test.logcdf.js	negative_mean	513
test/test.logcdf.js	large_variance	1025
test/test.factory.js	positive_mean	513
test/test.factory.js	negative_mean	513
test/test.factory.js	large_variance	1025
test/test.native.js	positive_mean	513
test/test.native.js	negative_mean	513
test/test.native.js	large_variance	1025

Each bound is the exact maximum observed ULP difference over its fixture: lowering any of them by one (512/1024) fails three assertions per file. The JavaScript and C implementations returned bit-identical results for every fixture value, so the same bounds apply in test/test.native.js as in the JavaScript tests.

For reference, the previous relative tolerances were 600.0 * EPS (positive_mean, negative_mean) and 800.0 * EPS (large_variance), which correspond to looser accuracy budgets than the ULP bounds above, so this is a tightening rather than a relaxation.

Related Issues

Does this pull request have any related issues?

This pull request has the following related issues:

• [RFC]: Migrate math/base/special packages from relative tolerance testing to ULP difference testing (tracking issue) #11352

Questions

Any questions for reviewers of this pull request?

No.

Other

Any other information relevant to this pull request? This may include screenshots, references, and/or implementation notes.

• Verification: test/test.js (3 assertions), test/test.logcdf.js (3016 assertions), test/test.factory.js (3019 assertions), and test/test.native.js (3016 assertions) all pass. The native add-on was built locally so that test/test.native.js was actually exercised rather than skipped.
• The full suite was run twice at the final bounds to confirm determinism (no FMA/architecture-dependent variation).
• ESLint (tests configuration, etc/eslint/.eslintrc.tests.js) is clean for all changed files.

Checklist

Please ensure the following tasks are completed before submitting this pull request.

• Read, understood, and followed the contributing guidelines.

AI Assistance

When authoring the changes proposed in this PR, did you use any kind of AI assistance?

• Yes
• No

If you answered "yes" above, how did you use AI assistance?

• Code generation (e.g., when writing an implementation or fixing a bug)
• Test/benchmark generation
• Documentation (including examples)
• Research and understanding

Disclosure

If you answered "yes" to using AI assistance, please provide a short disclosure indicating how you used AI assistance. This helps reviewers determine how much scrutiny to apply when reviewing your contribution.

This PR was authored by Claude Code as part of an automated, mechanical migration of existing test assertions to ULP-based assertions, following the idiom established in previously merged PRs referencing #11352. The ULP bounds were determined empirically by running the fixtures and minimizing the accepted bound.

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@stdlib-js/reviewers

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Generated by Claude Code

[stdlib-bot]

Hello! 👋

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Now that you've made a few contributions, we suggest no longer working on good first issues. Instead, we encourage you to prioritize cleaning up any PRs which have yet to be merged and then proceed to work on more involved tasks.

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[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/base/dists/cosine/logcdf	$\\color{green}299/299$ $\\color{green}+100.00\\%$	$\\color{green}33/33$ $\\color{green}+100.00\\%$	$\\color{green}4/4$ $\\color{green}+100.00\\%$	$\\color{green}299/299$ $\\color{green}+100.00\\%$

The above coverage report was generated for the changes in this PR.