docs: add examples

[Planeshifter]

Description

What is the purpose of this pull request?

This pull request:

• adds benchmarks to @stdlib/stats/kde2d and adds missing main-function JSDoc examples to four @stdlib/stats packages, bringing each outlier in line with its siblings.

@stdlib/stats/kde2d

Only non-namespace stats package without benchmarks. Adds benchmark/benchmark.js (present in 56/57 siblings, 98%), covering the default call and the n option, and the matching directories.benchmark entry in package.json (98%). Benchmark structure follows stats/lowess.

@stdlib/stats/anova1

Main function JSDoc in lib/main.js lacked an @example (present in 52/57 siblings, 91%). Example taken from lib/index.js, with the multi-line /* returns */ block collapsed to // returns {...}.

@stdlib/stats/binomial-test

Main function JSDoc in lib/main.js lacked an @example (91% of siblings). Adds both examples from lib/index.js: default call and custom p/alpha options.

@stdlib/stats/ttest2

Main function JSDoc in lib/main.js lacked an @example (91% of siblings). Uses the Student's sleep data from the README rather than the incrspace-based module example, so the example is self-contained.

@stdlib/stats/ztest2

Main function JSDoc in lib/main.js lacked an @example (91% of siblings). Example taken verbatim from lib/index.js, minus the require line.

Related Issues

Does this pull request have any related issues?

None.

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.

Namespace summary. @stdlib/stats has 62 direct child packages; the 5 namespace aggregators (array, base, incr, iter, strided) were excluded, leaving 57 voting members (majority threshold: 43, or 75%). Analyzed features: file tree, package.json key sets (top-level, scripts, directories), README ##/### sections, manifest.json keys, test/benchmark/example file names, public signature, return kind, validation prologue, error construction, JSDoc shape, and @stdlib dependencies. Features with a clear majority: file tree, package.json keys, README ## Usage/## Examples, return kind, JSDoc @returns/@throws/param descriptions, and JSDoc @example. Features without a clear majority, excluded: README ## Notes (70%), test.assign.js/benchmark.assign.js (65%, ndarray reductions only), error construction (format 46%, plain-string 49%, mixed 5%), and public signature (11 distinct shapes).

Validation. Structural features were extracted from the filesystem. Semantic features were extracted from lib/main.js, lib/index.js and lib/validate.js by agents. Each candidate was then checked by three separate agent reviews: semantic intent, cross-referencing tests, examples and docs, and structural applicability. Before review, benchmark presence was confirmed stdlib-wide (92% of packages with a lib/main.js). Excluded: package-specific implementation files, and stats/lowess. Its main function is declared as main, so a lowess( ... ) example with a // returns annotation would fail stdlib/jsdoc-doctest; that one needs a maintainer decision. Smoke-tested locally: the kde2d benchmark (via a harness shim, since node_modules is not installed) and every added example call.

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. Example disclosures: "This PR was written primarily by Claude Code." or "I consulted ChatGPT to understand the codebase, but the proposed changes were fully authored manually by myself.".

This PR was written primarily by Claude Code as part of an automated cross-package API drift detection run (majority vote across @stdlib/stats packages).

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🤖 Generated with Claude Code

https://claude.ai/code/session_01LMYQtSzimuL2KBLtWEqocz

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Generated by Claude Code

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/anova1	$\\color{red}739/752$ $\\color{green}+0.00\\%$	$\\color{red}61/65$ $\\color{green}+0.00\\%$	$\\color{green}10/10$ $\\color{green}+0.00\\%$	$\\color{red}739/752$ $\\color{green}+0.00\\%$
stats/binomial-test	$\\color{red}433/447$ $\\color{green}+0.00\\%$	$\\color{red}73/79$ $\\color{green}+0.00\\%$	$\\color{green}5/5$ $\\color{green}+0.00\\%$	$\\color{red}433/447$ $\\color{green}+0.00\\%$
stats/ttest2	$\\color{green}423/423$ $\\color{green}+0.00\\%$	$\\color{green}71/71$ $\\color{green}+0.00\\%$	$\\color{green}3/3$ $\\color{green}+0.00\\%$	$\\color{green}423/423$ $\\color{green}+0.00\\%$
stats/ztest2	$\\color{green}400/400$ $\\color{green}+0.00\\%$	$\\color{green}61/61$ $\\color{green}+0.00\\%$	$\\color{green}3/3$ $\\color{green}+0.00\\%$	$\\color{green}400/400$ $\\color{green}+0.00\\%$

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