69 lines
1.9 KiB
JavaScript
69 lines
1.9 KiB
JavaScript
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/**
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* @license Fraction.js v2.7.0 01/06/2015
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* http://www.xarg.org/2014/03/rational-numbers-in-javascript/
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*
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* Copyright (c) 2015, Robert Eisele (robert@xarg.org)
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* Dual licensed under the MIT or GPL Version 2 licenses.
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**/
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// NOTE: This is a nice example, but a stable version of this is served with Polynomial.js:
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// https://github.com/infusion/Polynomial.js
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var Fraction = require('../fraction.min.js');
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function integrate(poly) {
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poly = poly.replace(/\s+/g, "");
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var regex = /(\([+-]?[0-9/]+\)|[+-]?[0-9/]+)x(?:\^(\([+-]?[0-9/]+\)|[+-]?[0-9]+))?/g;
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var arr;
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var res = {};
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while (null !== (arr = regex.exec(poly))) {
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var a = (arr[1] || "1").replace("(", "").replace(")", "").split("/");
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var b = (arr[2] || "1").replace("(", "").replace(")", "").split("/");
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var exp = new Fraction(b).add(1);
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var key = "" + exp;
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if (res[key] !== undefined) {
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res[key] = {x: new Fraction(a).div(exp).add(res[key].x), e: exp};
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} else {
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res[key] = {x: new Fraction(a).div(exp), e: exp};
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}
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}
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var str = "";
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var c = 0;
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for (var i in res) {
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if (res[i].x.s !== -1 && c > 0) {
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str += ("+");
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} else if (res[i].x.s === -1) {
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str += ("-");
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}
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if (res[i].x.n / res[i].x.d !== 1) {
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if (res[i].x.d !== 1) {
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str += ("" + res[i].x.n + "/" + res[i].x.d + "");
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} else {
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str += ("" + res[i].x.n);
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}
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}
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str += ("x");
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if (res[i].e.n / res[i].e.d !== 1) {
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str += ("^");
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if (res[i].e.d !== 1) {
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str += ("(" + res[i].e.n + "/" + res[i].e.d + ")");
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} else {
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str += ("" + res[i].e.n);
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}
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}
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c++;
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}
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return str;
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}
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var poly = "-2/3x^3-2x^2+3x+8x^3-1/3x^(4/8)";
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console.log("f(x): " + poly);
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console.log("F(x): " + integrate(poly));
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