feat: add C implementation for `stats/base/dists/studentized-range/cdf` by nirmaljb · Pull Request #10106 · stdlib-js/stdlib

nirmaljb · 2026-02-05T17:01:42Z

Resolves #3887.

Description

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This pull request:

Adds a C implementation of the studentized-range cumulative distribution function (CDF).
Includes benchmarks for the C implementation.
Provides examples demonstrating the usage of the studentized-range CDF in C.

Related Issues

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This pull request has the following related issues:

[RFC]: Add C implementation for @stdlib/stats/base/dists/studentized-range/cdf #3887

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stdlib-bot · 2026-02-05T17:04:59Z

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/base/dists/studentized-range/cdf	$\\color{red}708/770$ $\\color{red}-0.03\\%$	$\\color{red}70/88$ $\\color{green}+0.00\\%$	$\\color{green}10/10$ $\\color{green}+0.00\\%$	$\\color{red}708/770$ $\\color{red}-0.03\\%$

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

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Planeshifter

Thanks for your contribution! Left round of feedback.

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Neerajpathak07 · 2026-07-16T08:24:26Z

+	v = R_DATA.v;
+	for ( i = 0; i < x.length; i++ ) {
+		y = cdf( x[i], r[i], v[i], 1.0 );
+		t.strictEqual( roundn( y, -2 ), roundn( expected[i], -2 ), 'x: '+x[i]+', r: '+r[i]+', v: '+v[i]+', y: '+y+', expected: '+expected[i] );


@Planeshifter one of the things that I am concerned about these test cases is that while testing with the standard ULP diff strategy the diffs reach as high as >3000 which is pretty large.

Here, would sticking to the current roundnusage were we round both the expected and values returned by the function hold true?

We shouldn't be rounding like this.

Yeah I realised this and haven't changed these yet since the prerequisite test.cdf.js used roundn will have to modernise those as well.
Re:- https://github.com/stdlib-js/stdlib/blob/develop/lib/node_modules/%40stdlib/stats/base/dists/studentized-range/cdf/test/test.cdf.js#L75

But the question remains to figure out how to reduce the ULP Diffs. Since while testing these easily go beyond 3000.

One plausible reason I feel the diffs are this high is due to the large generated fixtures against which these are being tested. Maybe updating those can be a an entry point?

- Add space after `if`, `for`, `while`, and `else if` keywords - Remove unused `pdf` variable in `apnorm` function - Change `found` from `double` to `int32_t` and use 0/1 instead of false/true - Fix incorrect `@example` return value from `~0.8644` to `~0.0644` - Fix `nranges` parameter doc to not use bracket notation in C - Separate variable declarations from initializations - Add section markers (VARIABLES, FUNCTIONS, MAIN) - Simplify `pow(exp(1), x)` to `exp(x)` in `prangeVInf` - Add blank line after license header and includes - Inline `pdf` computation in continued-fraction branch of `apnorm` Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> --- type: pre_commit_static_analysis_report description: Results of running static analysis checks when committing changes. report: - task: lint_filenames status: passed - task: lint_editorconfig status: passed - task: lint_markdown_pkg_readmes status: na - task: lint_markdown_docs status: na - task: lint_markdown status: na - task: lint_package_json status: na - task: lint_repl_help status: na - task: lint_javascript_src status: na - task: lint_javascript_cli status: na - task: lint_javascript_examples status: na - task: lint_javascript_tests status: na - task: lint_javascript_benchmarks status: passed - task: lint_python status: na - task: lint_r status: na - task: lint_c_src status: passed - task: lint_c_examples status: na - task: lint_c_benchmarks status: na - task: lint_c_tests_fixtures status: na - task: lint_shell status: na - task: lint_typescript_declarations status: passed - task: lint_typescript_tests status: na - task: lint_license_headers status: passed ---

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Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

…in.c Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

The previous examples called the CDF with only 2 arguments (missing v), which would return NaN. Replace with correct 3-argument calls. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

stdlib-bot added Statistics Issue or pull request related to statistical functionality. Needs Review A pull request which needs code review. Good First PR A pull request resolving a Good First Issue. labels Feb 5, 2026

nirmaljb marked this pull request as draft February 5, 2026 17:21

stdlib-bot removed the Needs Review A pull request which needs code review. label Feb 5, 2026

nirmaljb marked this pull request as ready for review February 5, 2026 17:43

stdlib-bot added the Needs Review A pull request which needs code review. label Feb 5, 2026

nirmaljb changed the title ~~feat: Add C implementation for stats/base/dists/studentized-range/cdf~~ feat: Add feat: Add C implementation for stats/base/dists/studentized_range/cdf Feb 5, 2026

nakul-krishnakumar changed the title ~~feat: Add feat: Add C implementation for stats/base/dists/studentized_range/cdf~~ feat: add C implementation for stats/base/dists/studentized-range/cdf Feb 5, 2026

stdlib-bot added the Merge Conflicts Pull request which has merge conflicts. label Feb 10, 2026

nirmaljb marked this pull request as draft February 10, 2026 17:35

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nirmaljb added 6 commits February 16, 2026 19:42

nirmaljb force-pushed the feat/studentized-range-cdf branch from 1e3bd36 to 240b121 Compare February 16, 2026 15:28

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Merge branch 'develop' into feat/studentized-range-cdf

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Neerajpathak07 requested a review from a team July 16, 2026 07:03

stdlib-bot added the Needs Review A pull request which needs code review. label Jul 16, 2026

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[RFC]: complete studentized-range CDF and quantile C support stdlib-js/metr-issue-tracker#1231

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Planeshifter and others added 3 commits August 29, 2026 00:51

refactor: remove C section markers from CDF main.c

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Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Planeshifter mentioned this pull request Aug 29, 2026

feat: add C implementation for stats/base/dists/studentized-range/quantile #14768

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Planeshifter and others added 2 commits August 29, 2026 01:22

refactor: use K&R brace style and consistent float literals in CDF ma…

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…in.c Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs: correct @example values in CDF index.js

1fbe5a4

The previous examples called the CDF with only 2 arguments (missing v), which would return NaN. Replace with correct 3-argument calls. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Planeshifter force-pushed the feat/studentized-range-cdf branch from 2222a5a to 1fbe5a4 Compare August 29, 2026 06:34

Planeshifter approved these changes Aug 29, 2026

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feat: add C implementation for `stats/base/dists/studentized-range/cdf` - #10106

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