43 lines
1.1 KiB
JavaScript
43 lines
1.1 KiB
JavaScript
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/*
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Fraction.js v5.0.0 10/1/2024
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https://raw.org/article/rational-numbers-in-javascript/
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Copyright (c) 2024, Robert Eisele (https://raw.org/)
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Licensed under the MIT license.
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*/
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var Fraction = require("fraction.js")
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function valueOfPi(val) {
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let minLen = Infinity, minI = 0, min = null;
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const choose = [val, val * Math.PI, val / Math.PI];
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for (let i = 0; i < choose.length; i++) {
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let el = new Fraction(choose[i]).simplify(1e-13);
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let len = Math.log(Number(el.n) + 1) + Math.log(Number(el.d));
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if (len < minLen) {
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minLen = len;
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minI = i;
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min = el;
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}
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}
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if (minI == 2) {
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return min.toFraction().replace(/(\d+)(\/\d+)?/, (_, p, q) =>
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(p == "1" ? "" : p) + "π" + (q || ""));
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}
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if (minI == 1) {
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return min.toFraction().replace(/(\d+)(\/\d+)?/, (_, p, q) =>
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p + (!q ? "/π" : "/(" + q.slice(1) + "π)"));
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}
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return min.toFraction();
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}
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console.log(valueOfPi(-3)); // -3
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console.log(valueOfPi(4 * Math.PI)); // 4π
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console.log(valueOfPi(3.14)); // 157/50
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console.log(valueOfPi(3 / 2 * Math.PI)); // 3π/2
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console.log(valueOfPi(Math.PI / 2)); // π/2
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console.log(valueOfPi(-1 / (2 * Math.PI))); // -1/(2π)
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