chore: align keyword outliers in stats/base/dists/negative-binomial

[Planeshifter]

Description

What is the purpose of this pull request?

This pull request aligns two package.json keywords-array outliers in @stdlib/stats/base/dists/negative-binomial with the sibling discrete-distribution convention. Metadata only; no source, test, or behavioral change.

Namespace summary

• Target namespace: @stdlib/stats/base/dists/negative-binomial
• Member count: 12 non-autogenerated members (cdf, ctor, kurtosis, logpmf, mean, mgf, mode, pmf, quantile, skewness, stdev, variance)
• Features analyzed: file tree, package.json top-level / scripts / directories / keywords shape, README ##/### heading sequence, manifest.json shape, test/benchmark/example filenames, public signature, returnKind, validation prologue, errorConstruction, JSDoc shape, require() dependencies.
• Features with clear majority (≥75%): package.json top-level key set (modulo gypfile) — 12/12; directories.{doc,example,lib,test,benchmark} — 12/12; README ## Usage/## Examples headings — 12/12; examples/index.js, docs/repl.txt, docs/types/index.d.ts, docs/types/test.ts, benchmark/benchmark.js, test/test.js presence — 12/12; 10 shared keywords (stdlib, stdmath, statistics, stats, distribution, dist, negative, binomial, univariate, discrete) — 12/12; .d.ts @param r description = "number of successes until experiment is stopped" — 12/12; (r, p)-signature summary-stat validation prologue isnan(r) || isnan(p) || r <= 0.0 || p < 0.0 || p > 1.0 → NaN — 6/6 within the summary-stat sub-cluster; "package's own function name present as a keyword" — 9/12 = 75%.
• Features without clear majority (excluded): binding.gyp / src/ / include/ / manifest.json / lib/native.js (7/12, tied to native-vs-JS package type); lib/factory.js (5/12, tied to whether the function has a factory form); LICENSE file at package root (2/12 present, 10/12 absent — removal is destructive, deferred); test/julia/ vs test/fixtures/julia/ data-fixture location (5/12 vs 1/12); lib/main.js JSDoc @param r "successes" vs "failures" (6/6 split — surfaced for a follow-up routine that aligns source-side JSDoc with .d.ts); per-function validation prologue across distribution functions (cdf, logpmf, pmf, quantile, mgf differ for sound mathematical reasons); errorConstruction (ctor uses format, others return NaN — intentional).

@stdlib/stats/base/dists/negative-binomial/mean

Adds mean, average, and avg to the keywords array in package.json, bringing @stdlib/stats/base/dists/negative-binomial/mean into conformance with all seven sibling discrete distribution mean packages (bernoulli/mean, binomial/mean, geometric/mean, hypergeometric/mean, poisson/mean, planck/mean, discrete-uniform/mean — 100% ecosystem conformance). PR #12647 (merged 2026-06-07) resolved the same gap in hypergeometric/mean and identified this package as the remaining outlier. Insertion position (between discrete and negative) mirrors bernoulli/mean and hypergeometric/mean. Metadata-only change; no source, tests, or behavior affected.

@stdlib/stats/base/dists/negative-binomial/pmf

The keywords array in package.json carries 'pdf' instead of 'pmf', misclassifying the negative binomial PMF as a continuous-distribution function. This contradicts the package name, description (Negative binomial distribution probability mass function (PMF).), README, the sibling negative-binomial/logpmf package (which already carries 'pmf'), and all seven other discrete-distribution pmf packages in the ecosystem (bernoulli, binomial, geometric, hypergeometric, poisson, planck, discrete-uniform — 100% carry 'pmf', 0% carry 'pdf'). Single in-place replacement of 'pdf' with 'pmf' in the keywords array; metadata only, no behavioral change.

Related Issues

Does this pull request have any related issues?

No.

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.

Validation

Checked:

• Structural feature extraction across all 12 members (file tree, package.json shape, keywords, directories, manifest.json, README headings, test/benchmark/example/lib filenames, .d.ts shape).
• Semantic feature extraction per package (lib/main.js, lib/index.js, lib/factory.js where present) via parallel per-package agents: publicSignature, factorySignature, returnKind, validation prologue, errorConstruction, JSDoc shape, require()-derived dependencies. The semantic extractor false-positived on kurtosis (reported empty validation prologue); manual re-read of kurtosis/lib/main.js confirmed the standard isnan(r) || isnan(p) || r <= 0.0 || p < 0.0 || p > 1.0 → NaN prologue is present, matching the 5 other (r, p)-signature summary-stat siblings.
• Three-agent drift validation on both surviving outliers:
  • Agent 1 (opus semantic-review): both confirmed-drift. README, JSDoc, and source semantics confirm pmf is a discrete PMF and mean is the standard expected value.
  • Agent 2 (opus cross-reference): both confirmed-drift. No test, example, or sibling-package code references the keyword strings; the only consumer is _tools/search/pkg-index/lib/create.js, which joins keywords into a free-text lunr-index blob (no structured contract).
  • Agent 3 (sonnet structural-review): both confirmed-drift. Insertion positions match sibling conventions exactly.
• Cross-run dedup: no open or recently-merged PR proposes either keyword change to these packages. Open PRs feat: add C implementation for stats/base/dists/negative-binomial/logpmf #10132 (adds C source for negative-binomial/logpmf) and docs: propagate fixes from develop to sibling packages #12677 (propagates the for a/an → and typo fix to negative-binomial/mgf/lib/factory.js) are disjoint from this run's outlier set.

Deliberately excluded:

• quantile keyword on negative-binomial/quantile — within-namespace function-name-as-keyword majority is 75% (just at threshold), but the sibling discrete-distribution convention is cdf, inverse without quantile (1/7 = 14% ecosystem-wide). Fails the ≥90% ecosystem-wide presence gate.
• lib/main.js JSDoc @param r "successes" vs "failures" — 6/6 split within the namespace; no within-namespace majority. Every .d.ts already carries "successes" (canonical per PR docs: fix typos and copy-paste errors in stats TypeScript declarations #12482). Flagged for a follow-up routine that reconciles source-side JSDoc against .d.ts.
• ctor README + error-message "trials" vs "successes" — internally inconsistent (ctor JSDoc and .d.ts say "successes"; README + thrown-error message say "trials"). Out of scope for a within-namespace majority routine; flagged for a docs PR.
• LICENSE files in pmf and logpmf — absent is the namespace majority (10/12) but removal is destructive and has publish-time implications. Out of mechanical-fix scope.
• density keyword on negative-binomial/pmf — 0/7 sibling discrete pmf packages carry density. Conservative one-shot drift PR keeps single-direction (add/swap) edits only; flag for a future pass.

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 via the cross-package drift-detection routine: the namespace @stdlib/stats/base/dists/negative-binomial was selected by uniform-random pick over the 123 eligible directories (≥8 direct child packages with package.json) under lib/node_modules/@stdlib/, structural and per-package semantic features were extracted across all 12 members, majority patterns were computed at the 75% conformance threshold, and three independent validation agents (opus semantic-review, opus cross-reference, sonnet structural-review) confirmed each correction as confirmed-drift before any file was edited. Both edits are package.json keywords array operations; no source, behavior, test, doc, or generator output is touched.

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@stdlib-js/reviewers

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Generated by Claude Code

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/base/dists/negative-binomial/mean	$\\color{green}193/193$ $\\color{green}+100.00\\%$	$\\color{green}11/11$ $\\color{green}+100.00\\%$	$\\color{green}2/2$ $\\color{green}+100.00\\%$	$\\color{green}193/193$ $\\color{green}+100.00\\%$
stats/base/dists/negative-binomial/pmf	$\\color{red}532/562$ $\\color{green}+94.66\\%$	$\\color{red}49/57$ $\\color{green}+85.96\\%$	$\\color{green}5/5$ $\\color{green}+100.00\\%$	$\\color{red}532/562$ $\\color{green}+94.66\\%$

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