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import { variance } from "./variance.ts";
/** * The [standard deviation](http://en.wikipedia.org/wiki/Standard_deviation) * is the square root of the variance. This is also known as the population * standard deviation. It's useful for measuring the amount * of variation or dispersion in a set of values. * * Standard deviation is only appropriate for full-population knowledge: for * samples of a population, {@link sampleStandardDeviation} is * more appropriate. * * @param {number[]} x input * @returns {number} standard deviation * @example * variance([2, 4, 4, 4, 5, 5, 7, 9]); // => 4 * standardDeviation([2, 4, 4, 4, 5, 5, 7, 9]); // => 2 */export function standardDeviation(x: number[]): number {    if (x.length === 1) {        return 0;    }
    const v = variance(x);    return Math.sqrt(v);}