feat: add `stats/base/dists/anglit/stdev` by Om-A-osc · Pull Request #11489 · stdlib-js/stdlib

Om-A-osc · 2026-04-16T19:37:01Z

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description: Results of running static analysis checks when committing changes. report:

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Progresses #9960.

Description

What is the purpose of this pull request?

This pull request:

adds stats/base/dists/anglit/stdev
implements the standard deviation for the Anglit distribution
includes unit tests and documentation
follows stdlib conventions and project structure

Related Issues

Does this pull request have any related issues?

This pull request has the following related issues:

[RFC]: Add anglit distribution implementation #9960

Questions

Any questions for reviewers of this pull request?

No.

Other

Any other information relevant to this pull request?

Implementation follows existing distribution mode modules and adheres to stdlib coding standards.

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

Code generation
Test/benchmark generation
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@stdlib-js/reviewers

stdlib-bot · 2026-04-16T19:40:45Z

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/base/dists/anglit/stdev	$\\color{green}180/180$ $\\color{green}+0.00\\%$	$\\color{green}9/9$ $\\color{green}+0.00\\%$	$\\color{green}2/2$ $\\color{green}+0.00\\%$	$\\color{green}180/180$ $\\color{green}+0.00\\%$

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

Neerajpathak07

@Om-A-osc Thank you for working on this!!! Left out a few comments.

Neerajpathak07 · 2026-04-19T15:08:33Z

+static double benchmark( void ) {
+	double elapsed;
+	double sigma[ 100 ];
+	double mu[ 100 ];


Suggested change

double mu[ 100 ];

static double benchmark( void ) {

double sigma[ 100 ];

double mu[ 100 ];

double elapsed;

Ordering by length

Neerajpathak07 · 2026-04-19T15:10:01Z

+// TypeScript Version: 4.1
+
+/**
+* Returns the standard deviation for an anglit distribution with location `mu` and scale `sigma`.


Suggested change

* Returns the standard deviation for an anglit distribution with location `mu` and scale `sigma`.

* Returns the standard deviation for an anglit distribution with location parameter `mu` and scale parameter `sigma`.

Feel free to update the description wherever relevant throughout the PR if you feel this makes more sense.

Neerajpathak07 · 2026-04-19T15:10:10Z

+    NaN
+
+    See Also
+    --------


Suggested change

--------

--------

Neerajpathak07 · 2026-04-19T15:17:26Z

+
+// VARIABLES //
+
+// sqrt( (π²/16) - (1/2) ):


Suggested change

// sqrt( (π²/16) - (1/2) ):

// sqrt( (π²/16) - (1/2) )

Neerajpathak07 · 2026-04-19T15:17:51Z

+#include "stdlib/stats/base/dists/anglit/stdev.h"
+#include "stdlib/math/base/assert/is_nan.h"
+
+static const double STDLIB_ANGLIT_STDEV_CONST = 0.3418336950449515; // sqrt( (π²/16) - (1/2) )


Using this const here would be acceptable as per discussed in the Office Hours conducted on April 14th.

Suggested change

static const double STDLIB_ANGLIT_STDEV_CONST = 0.3418336950449515; // sqrt( (π²/16) - (1/2) )

// sqrt( (π²/16) - (1/2) )

static const double STDEV_CONST = 0.3418336950449515;

Let's stay consist with the variable name as per used in the JS implementation. Also something which we closely follow for special math functions. Re:- powf

Neerajpathak07 · 2026-04-19T15:17:57Z

+		stdlib_base_is_nan( sigma ) ||
+		sigma <= 0.0
+	) {
+		return 0.0/0.0; // NaN


Suggested change

return 0.0/0.0; // NaN

return 0.0 / 0.0; // NaN

Neerajpathak07 · 2026-04-19T15:18:11Z

+
+    # Arguments
+
+    * `mean`: mean parameter (mu)


Suggested change

* `mean`: mean parameter (mu)

* `mean`: location parameter (mu)

mu here is a location parameter not mean.

Neerajpathak07 · 2026-04-19T15:18:14Z

+    # Examples
+
+    ``` python
+    python> mean = rand(1000) * 10.0 - 5.0


Same comment.

Neerajpathak07 · 2026-04-19T15:18:17Z

+    """Generate fixture data."""
+    mean = rand(1000) * 10.0 - 5.0
+    scale = rand(1000) * 10.0 + 1.0
+    gen(mean, scale, "data.json")


Would be better to do a clean-up on this runner file.

Neerajpathak07 · 2026-04-19T15:21:27Z

+
+The [standard deviation][stdev] for an [anglit][anglit-distribution] random variable with location parameter `mu` and scale parameter `sigma` is
+
+<!-- <equation class="equation" label="eq:anglit_stdev" align="center" raw="\operatorname{SD}(X) = \sigma \sqrt{\left({\frac{\pi^{2}}{16}}-\frac{1}{2}\right)}" alt="Standard deviation for an anglit distribution."> -->


While previewing the markdown documentation the equation is not generated here properly. Mind fixing that as well.
Re:-

--- 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 status: passed - task: lint_package_json status: passed - task: lint_repl_help status: passed - task: lint_javascript_src status: passed - task: lint_javascript_cli status: na - task: lint_javascript_examples status: passed - task: lint_javascript_tests status: passed - task: lint_javascript_benchmarks status: passed - task: lint_python status: passed - task: lint_r status: na - task: lint_c_src status: passed - task: lint_c_examples status: passed - task: lint_c_benchmarks status: passed - task: lint_c_tests_fixtures status: na - task: lint_shell status: na - task: lint_typescript_declarations status: passed - task: lint_typescript_tests status: passed - task: lint_license_headers status: passed ---

Apply reviewer feedback: - Rename the C constant to `STDEV_CONST` to match the JS variable name. - Reword the TSDoc summary to "location parameter `mu` and scale parameter `sigma`" across the JS, C, and TypeScript declarations. - Reorder the `benchmark/c/benchmark.c` local declarations by length. - Fix the `README.md` equation so it renders on GitHub by using `\mathop{\mathrm{SD}}` in the visible math block. - Clean up the Python fixture runner to name the location parameter `mu` (rather than `mean`) throughout. - Fix `See Also` divider spacing in the REPL help text. --- 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: passed - task: lint_markdown_docs status: na - task: lint_markdown status: na - task: lint_package_json status: na - task: lint_repl_help status: passed - task: lint_javascript_src status: passed - task: lint_javascript_cli status: na - task: lint_javascript_examples status: na - task: lint_javascript_tests status: na - task: lint_javascript_benchmarks status: na - task: lint_python status: missing_dependencies - task: lint_r status: na - task: lint_c_src status: passed - task: lint_c_examples status: na - task: lint_c_benchmarks status: passed - task: lint_c_tests_fixtures status: na - task: lint_shell status: na - task: lint_typescript_declarations status: passed - task: lint_typescript_tests status: passed - task: lint_license_headers status: passed ---

The Python argument/variable name `mu` (2 chars) fails pylint's invalid-name check (C0103), which requires >=3 characters. Rename the identifier to `loc` while keeping the JSON output key `mu` unchanged, as the test reads `data.mu`. --- 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: na - task: lint_python status: missing_dependencies - task: lint_r status: na - task: lint_c_src status: na - 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 ---

Planeshifter

Let's land! Thanks, @Om-A-osc!

stdlib-bot · 2026-07-05T06:24:33Z

PR Commit Message

feat: add `stats/base/dists/anglit/stdev`

PR-URL: https://github.com/stdlib-js/stdlib/pull/11489
Ref: https://github.com/stdlib-js/stdlib/issues/9960

Co-authored-by: Philipp Burckhardt <pburckhardt@outlook.com>
Reviewed-by: Neeraj Pathak <neerajrpathak710@gmail.com>
Reviewed-by: Philipp Burckhardt <pburckhardt@outlook.com>

Please review the above commit message and make any necessary adjustments.

Feedback addressed.

Om-A-osc requested a review from a team April 16, 2026 19:37

stdlib-bot added Statistics Issue or pull request related to statistical functionality. Needs Review A pull request which needs code review. labels Apr 16, 2026

Neerajpathak07 previously requested changes Apr 19, 2026

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Neerajpathak07 added Needs Changes Pull request which needs changes before being merged. and removed Needs Review A pull request which needs code review. labels Apr 19, 2026

Planeshifter mentioned this pull request Jul 5, 2026

Clean-up and land statistical distribution PRs stdlib-js/metr-issue-tracker#966

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Planeshifter force-pushed the feat/stats-base-dists-anglit-stdev branch from 9c85ee6 to 3b160f0 Compare July 5, 2026 05:39

Om-A-osc and others added 3 commits July 5, 2026 01:17

Planeshifter force-pushed the feat/stats-base-dists-anglit-stdev branch from 3b160f0 to 94db516 Compare July 5, 2026 06:17

Planeshifter approved these changes Jul 5, 2026

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Planeshifter merged commit f2d8482 into stdlib-js:develop Jul 5, 2026
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	* Returns the standard deviation for an anglit distribution with location `mu` and scale `sigma`.
	* Returns the standard deviation for an anglit distribution with location parameter `mu` and scale parameter `sigma`.

	static const double STDLIB_ANGLIT_STDEV_CONST = 0.3418336950449515; // sqrt( (π²/16) - (1/2) )
	// sqrt( (π²/16) - (1/2) )
	static const double STDEV_CONST = 0.3418336950449515;

	* `mean`: mean parameter (mu)
	* `mean`: location parameter (mu)


		The [standard deviation][stdev] for an [anglit][anglit-distribution] random variable with location parameter `mu` and scale parameter `sigma` is

		<!-- <equation class="equation" label="eq:anglit_stdev" align="center" raw="\operatorname{SD}(X) = \sigma \sqrt{\left({\frac{\pi^{2}}{16}}-\frac{1}{2}\right)}" alt="Standard deviation for an anglit distribution."> -->

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