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/* eslint no-shadow: 0 */
const test = require("tap").test;const ss = require("../dist/simple-statistics.js");
function rnd(x) {    return Math.round(x * 1000) / 1000;}
test("sample correlation", function (t) {    t.test("can get the sample correlation of identical arrays", function (t) {        const data = [1, 2, 3, 4, 5, 6];        t.equal(rnd(ss.sampleCorrelation(data, data)), 1);        t.end();    });
    t.test("can get the sample correlation of different arrays", function (t) {        const a = [1, 2, 3, 4, 5, 6];        const b = [2, 2, 3, 4, 5, 60];        t.equal(rnd(ss.sampleCorrelation(a, b)), 0.691);        t.end();    });
    t.test("zero-length corner case", function (t) {        t.throws(function () {            ss.sampleCorrelation([], []);        });        t.end();    });
    t.end();});
test("sample rank correlation", function (t) {    t.test(        "absolute rank correlation for monotonic function equals one",        function (t) {            const x = [1, 2, 3, 4, 5, 6];            let y;            for (const sign of [-1, 1]) {                y = x.map((a) => sign * a * a);                if (rnd(ss.sampleRankCorrelation(x, y)) !== sign * 1) {                    t.fail("absolute rank correlation not equal to one");                }            }            t.end();        }    );
    t.test("rank correlation agrees with R calculation", function (t) {        const x = [            -0.008718749, -0.06111878, 0.067698537, -1.075537181, 0.041328545,            0.56687373, 0.193619496, -2.057133298, -1.058808987, -0.173177955        ];        const y = [            -3.02455481, -1.30596109, 0.03873244, -1.27909938, -0.24630809,            -0.18103793, -0.48281339, -2.78997293, -1.30551335, -1.63361636        ];        const rankCorr = 0.6484848; // calculated using cor(x, y, method = "spearman") in R        if (Math.abs(ss.sampleRankCorrelation(x, y) - rankCorr) > ss.epsilon) {            console.log(ss.sampleRankCorrelation(x, y));            t.fail("rank correlation is incorrect for sample data");        }        t.end();    });    t.end();});