test: migrate stats/incr/pcorrdistmat to ULP-based assertions

[kgryte]

Resolves a part of #11352.

Description

What is the purpose of this pull request?

This pull request:

• migrates the tests for stats/incr/pcorrdistmat from relative tolerance testing to ULP difference testing, per [RFC]: Migrate math/base/special packages from relative tolerance testing to ULP difference testing (tracking issue) #11352.
• replaces the four delta/tol (3.0 * EPS * abs( e )) comparisons in test/test.js with t.strictEqual( isAlmostSameValue( v, e, N ), true, 'returns expected value' );, adding the @stdlib/assert/is-almost-same-value import and removing the now unused @stdlib/math/base/special/abs and @stdlib/constants/float64/eps imports.

Final ULP constants:

Test	ULP bound
...correlation distance matrix (order)	0
...correlation distance matrix (distance matrix)	0
...correlation distance matrix (order, means)	1
...correlation distance matrix (distance matrix, means)	1

These are the measured minimums. Starting from a high bound and tightening, the maximum ULP difference over the full set of hard-coded Julia-derived expected values is exactly 0, 0, 1, and 1, respectively. The two unknown-means tests are exact matches (0 is the floor), and the two known-means bounds were verified to be minimal: lowering either from 1 to 0 produces failing assertions (8 failures in total).

The test data is fully deterministic (hard-coded Float64Array inputs, no PRNG), and the suite was run twice at the final bounds with identical results:

• test/test.js: 212 passing, 0 failing

make lint-javascript-tests TESTS_FILTER=".*/stats/incr/pcorrdistmat/.*" is clean. This package has no test/test.native.js, so test/test.js is the only changed file.

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.

The conversion mirrors the sibling package stats/incr/pcorrmat, which has the same four-block test structure and per-block ULP bounds.

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

This PR was authored by Claude Code running as an automated task. The tolerance-to-ULP conversion, the search for the minimum ULP bounds, and the local test/lint verification were all performed by Claude Code.

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@stdlib-js/reviewers

🤖 Generated with Claude Code

https://claude.ai/code/session_01B1SNYoWzDxPfm4UmswRuZE

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Generated by Claude Code

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/incr/pcorrdistmat	$\\color{green}534/534$ $\\color{green}+100.00\\%$	$\\color{green}45/45$ $\\color{green}+100.00\\%$	$\\color{green}5/5$ $\\color{green}+100.00\\%$	$\\color{green}534/534$ $\\color{green}+100.00\\%$

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