locutus/python/statistics/harmonic_mean.js

Locutus other languages' standard libraries to JavaScript for fun and educational purposes

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.harmonic_mean = harmonic_mean;
const _statistics_ts_1 = require("../_helpers/_statistics.js");
function harmonic_mean(data, weights) {
    //      discuss at: https://locutus.io/python/statistics/harmonic_mean/
    // parity verified: Python 3.12
    //     original by: Kevin van Zonneveld (https://kvz.io)
    //          note 1: Returns the harmonic mean and supports optional positive weights.
    //       example 1: harmonic_mean([40, 60])
    //       returns 1: 47.99999999999999
    //       example 2: harmonic_mean([40, 60], [5, 30])
    //       returns 2: 56
    //       example 3: harmonic_mean([0, 10])
    //       returns 3: 0
    const values = (0, _statistics_ts_1.assertStatisticsArray)(data, 'harmonic_mean').map((value) => (0, _statistics_ts_1.toStatisticNumber)(value, 'harmonic_mean'));
    if (values.length < 1) {
        throw new Error('harmonic_mean requires at least one data point');
    }
    if (values.length === 1 && weights === undefined) {
        const value = values[0] ?? 0;
        if (value < 0) {
            throw new Error('harmonic mean does not support negative values');
        }
        return value;
    }
    const errmsg = 'harmonic mean does not support negative values';
    const weightValues = weights === undefined
        ? new Array(values.length).fill(1)
        : (0, _statistics_ts_1.assertStatisticsArray)(weights, 'harmonic_mean').map((value) => (0, _statistics_ts_1.toStatisticNumber)(value, 'harmonic_mean'));
    if (weightValues.length !== values.length) {
        throw new Error('Number of weights does not match data size');
    }
    if (weightValues.some((value) => value < 0) || values.some((value) => value < 0)) {
        throw new Error(errmsg);
    }
    const sumWeights = weightValues.reduce((sum, value) => sum + value, 0);
    try {
        let total = 0;
        for (let index = 0; index < values.length; index += 1) {
            const value = values[index] ?? 0;
            const weight = weightValues[index] ?? 0;
            total += weight ? weight / value : 0;
        }
        if (total <= 0) {
            throw new Error('Weighted sum must be positive');
        }
        return sumWeights / total;
    }
    catch (error) {
        if (error instanceof Error && error.message === 'Weighted sum must be positive') {
            throw error;
        }
        return 0;
    }
}