als-statistics/tests/ratio-column/instruments/weighted-mean.test.js

A powerful and lightweight JavaScript library for descriptive statistics, regression, clustering, outlier detection, and noise analysis using a flexible table/column architecture.

const { describe, it } = require('node:test');
const assert = require('node:assert');
const weightedMean = require('../../../lib/ratio-column/instruments/weighted-mean');

describe('weightedMean function', () => {
   it('should compute weighted mean correctly', () => {
      const values = [10, 20, 30];
      const weights = [1, 2, 3];
      assert.strictEqual(weightedMean(weights, values).toFixed(2), '23.33');
   });

   it('should return 0 when weights sum to 0', () => {
      const values = [10, 20, 30];
      const weights = [0, 0, 0];
      assert.strictEqual(weightedMean(weights, values), 0);
   });

   it('should throw error for mismatched lengths', () => {
      const values = [10, 20, 30];
      const weights = [1, 2];
      assert.throws(() => weightedMean(weights, values), /Weights must be an array of the same length as values/);
   });
});