hierarchical-estimates-visu.../packages/webpage-refactor/lib/coefficientOfVariation.js

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const sum = (arr) => arr.reduce((a, b) => a + b, 0);
function getStdev(arr) {
if (Array.isArray(arr) && arr.length > 0) {
const n = arr.length;
const mean = arr.reduce((a, b) => a + b) / n;
return Math.sqrt(
arr.map((x) => Math.pow(x - mean, 2)).reduce((a, b) => a + b) / n
);
} else {
return 0;
}
}
export const avg = (arr) => sum(arr) / arr.length;
export const geomMean = (arr) => {
let n = arr.length;
let logavg = sum(arr.map((x) => Math.log(x))); // works for low numbers much better, numerically
let result = Math.exp(logavg / n);
return result;
};
export const getCoefficientOfVariation = (arr) => {
let nonPositiveNumbers = arr.filter((x) => x <= 0);
if (nonPositiveNumbers.length == 0) {
let gm = geomMean(arr);
let stdev = getStdev(arr);
return stdev / gm;
} else {
return getStdev(arr) / avg(arr);
}
};