simple-statistics/src/quantile_rank.js

Simple Statistics

import numericSort from "./numeric_sort.js";
import quantileRankSorted from "./quantile_rank_sorted.js";

/**
 * This function returns the quantile in which one would find the given value in
 * the given array. It will copy and sort your array before each run, so
 * if you know your array is already sorted, you should use `quantileRankSorted`
 * instead.
 *
 * @param {Array<number>} x input
 * @returns {number} value value
 * @example
 * quantileRank([4, 3, 1, 2], 3); // => 0.75
 * quantileRank([4, 3, 2, 3, 1], 3); // => 0.7
 * quantileRank([2, 4, 1, 3], 6); // => 1
 * quantileRank([5, 3, 1, 2, 3], 4); // => 0.8
 */
function quantileRank(x, value) {
    // Cloning and sorting the array
    const sortedCopy = numericSort(x);

    return quantileRankSorted(sortedCopy, value);
}

export default quantileRank;