als-statistics/goldens/tests/compare-means.js

Modular JS statistics toolkit for Node.js and the browser: descriptive stats, correlations (Pearson/Spearman/Kendall), t-tests & ANOVA (Student/Welch), reliability (Cronbach’s alpha), regression (linear/logistic), clustering (DBSCAN/HDBSCAN), and table/co

import { EPS } from "../settings.js";
import { Analyze } from "../../lib/index.js";
const { CompareMeans } = Analyze
import { describe, it } from 'node:test';
import assert from 'node:assert/strict';
import { nearlyEqual, hasDataOrSkip, splitGroups, toRecordFromArray } from '../helpers.js'

export function testCompareMeans(g) {
   const { X, Y, group, score, before, after, Q1, Q2, Q3, Q4 } = g.data;
   describe('Compare Means (CompareMeans)', () => {
      const groupsObj = splitGroups(score, group, 3);
      const cm = new CompareMeans(groupsObj);
   
      it('Independent Student (0 vs 1)', () => {
         const res = cm.independent('0', '1');
         const g0 = g.compare_means.independent_student;
         nearlyEqual(res.t, g0.t, 5e-6, 'ttest student t');
         nearlyEqual(res.p, g0.p, 5e-6, 'ttest student p');
         nearlyEqual(res.df, g0.df, EPS.df, 'ttest student df');
      });
   
      it('Independent Welch (0 vs 1)', () => {
         const res = cm.independentWelch('0', '1');
         const g0 = g.compare_means.independent_welch;
         nearlyEqual(res.t, g0.t, 5e-6, 'ttest welch t');
         nearlyEqual(res.p, g0.p, 5e-6, 'ttest welch p');
         nearlyEqual(res.df, g0.df, 5e-4, 'ttest welch df'); // Satterthwaite df can vary slightly
      });
   
      it('Paired (before vs after)', () => {
         const c2 = new CompareMeans({ before, after });
         const res = c2.paired('before', 'after');
         const g0 = g.compare_means.paired;
         nearlyEqual(res.t, g0.t, 5e-6, 'paired t');
         nearlyEqual(res.p, g0.p, 5e-6, 'paired p');
         assert.equal(res.df, g0.df, 'paired df');
      });
   
      it('One-sample (X vs mu0)', () => {
         const mu0 = g.compare_means.one_sample.mu0;
         const c3 = new CompareMeans({ X });
         const res = c3.oneSample('X', mu0);
         const g0 = g.compare_means.one_sample;
         nearlyEqual(res.t, g0.t, 5e-6, 'one-sample t');
         nearlyEqual(res.p, g0.p, 5e-6, 'one-sample p');
         assert.equal(res.df, g0.df, 'one-sample df');
      });
   
      it('One-way ANOVA (classic & Welch)', () => {
         const aClassic = cm.anova('0', '1', '2');
         const aWelch = cm.anovaWelch('0', '1', '2');
         const gC = g.compare_means.anova;
         const gW = g.compare_means.anova_welch;
   
         nearlyEqual(aClassic.F, gC.F, EPS.anovaF, 'anova F');
         nearlyEqual(aClassic.p, gC.p, EPS.p, 'anova p');
         assert.equal(aClassic.dfBetween, gC.dfBetween, 'anova dfBetween');
         assert.equal(aClassic.dfWithin, gC.dfWithin, 'anova dfWithin');
   
         nearlyEqual(aWelch.F, gW.F, 5e-6, 'welch anova F');
         nearlyEqual(aWelch.p, gW.p, 5e-6, 'welch anova p');
         nearlyEqual(aWelch.dfBetween, gW.dfBetween, 5e-6, 'welch anova dfBetween');
         nearlyEqual(aWelch.dfWithin, gW.dfWithin, 1e-3, 'welch anova dfWithin'); // df2 is approximate
      });
   });

}