/** * @license Fraction.js v4.2.0 23/05/2021 * https://www.xarg.org/2014/03/rational-numbers-in-javascript/ * * Copyright (c) 2021, Robert Eisele (robert@xarg.org) * Dual licensed under the MIT or GPL Version 2 licenses. **/ /** * * This class offers the possibility to calculate fractions. * You can pass a fraction in different formats. Either as array, as double, as string or as an integer. * * Array/Object form * [ 0 => , 1 => ] * [ n => , d => ] * * Integer form * - Single integer value * * Double form * - Single double value * * String form * 123.456 - a simple double * 123/456 - a string fraction * 123.'456' - a double with repeating decimal places * 123.(456) - synonym * 123.45'6' - a double with repeating last place * 123.45(6) - synonym * * Example: * * let f = new Fraction("9.4'31'"); * f.mul([-4, 3]).div(4.9); * */ (function(root) { "use strict"; // Set Identity function to downgrade BigInt to Number if needed if (!BigInt) BigInt = function(n) { if (isNaN(n)) throw new Error(""); return n; }; const C_ONE = BigInt(1); const C_ZERO = BigInt(0); const C_TEN = BigInt(10); const C_TWO = BigInt(2); const C_FIVE = BigInt(5); // Maximum search depth for cyclic rational numbers. 2000 should be more than enough. // Example: 1/7 = 0.(142857) has 6 repeating decimal places. // If MAX_CYCLE_LEN gets reduced, long cycles will not be detected and toString() only gets the first 10 digits const MAX_CYCLE_LEN = 2000; // Parsed data to avoid calling "new" all the time const P = { "s": C_ONE, "n": C_ZERO, "d": C_ONE }; function assign(n, s) { try { n = BigInt(n); } catch (e) { throw Fraction['InvalidParameter']; } return n * s; } // Creates a new Fraction internally without the need of the bulky constructor function newFraction(n, d) { if (d === C_ZERO) { throw Fraction['DivisionByZero']; } const f = Object.create(Fraction.prototype); f["s"] = n < C_ZERO ? -C_ONE : C_ONE; n = n < C_ZERO ? -n : n; const a = gcd(n, d); f["n"] = n / a; f["d"] = d / a; return f; } function factorize(num) { const factors = {}; let n = num; let i = C_TWO; let s = C_FIVE - C_ONE; while (s <= n) { while (n % i === C_ZERO) { n/= i; factors[i] = (factors[i] || C_ZERO) + C_ONE; } s+= C_ONE + C_TWO * i++; } if (n !== num) { if (n > 1) factors[n] = (factors[n] || C_ZERO) + C_ONE; } else { factors[num] = (factors[num] || C_ZERO) + C_ONE; } return factors; } const parse = function(p1, p2) { let n = C_ZERO, d = C_ONE, s = C_ONE; if (p1 === undefined || p1 === null) { /* void */ } else if (p2 !== undefined) { n = BigInt(p1); d = BigInt(p2); s = n * d; if (n % C_ONE !== C_ZERO || d % C_ONE !== C_ZERO) { throw Fraction['NonIntegerParameter']; } } else if (typeof p1 === "object") { if ("d" in p1 && "n" in p1) { n = BigInt(p1["n"]); d = BigInt(p1["d"]); if ("s" in p1) n*= BigInt(p1["s"]); } else if (0 in p1) { n = BigInt(p1[0]); if (1 in p1) d = BigInt(p1[1]); } else if (p1 instanceof BigInt) { n = BigInt(p1); } else { throw Fraction['InvalidParameter']; } s = n * d; } else if (typeof p1 === "bigint") { n = p1; s = p1; d = BigInt(1); } else if (typeof p1 === "number") { if (isNaN(p1)) { throw Fraction['InvalidParameter']; } if (p1 < 0) { s = -C_ONE; p1 = -p1; } if (p1 % 1 === 0) { n = BigInt(p1); } else if (p1 > 0) { // check for != 0, scale would become NaN (log(0)), which converges really slow let z = 1; let A = 0, B = 1; let C = 1, D = 1; let N = 10000000; if (p1 >= 1) { z = 10 ** Math.floor(1 + Math.log10(p1)); p1/= z; } // Using Farey Sequences while (B <= N && D <= N) { let M = (A + C) / (B + D); if (p1 === M) { if (B + D <= N) { n = A + C; d = B + D; } else if (D > B) { n = C; d = D; } else { n = A; d = B; } break; } else { if (p1 > M) { A+= C; B+= D; } else { C+= A; D+= B; } if (B > N) { n = C; d = D; } else { n = A; d = B; } } } n = BigInt(n) * BigInt(z); d = BigInt(d); } } else if (typeof p1 === "string") { let ndx = 0; let v = C_ZERO, w = C_ZERO, x = C_ZERO, y = C_ONE, z = C_ONE; let match = p1.match(/\d+|./g); if (match === null) throw Fraction['InvalidParameter']; if (match[ndx] === '-') {// Check for minus sign at the beginning s = -C_ONE; ndx++; } else if (match[ndx] === '+') {// Check for plus sign at the beginning ndx++; } if (match.length === ndx + 1) { // Check if it's just a simple number "1234" w = assign(match[ndx++], s); } else if (match[ndx + 1] === '.' || match[ndx] === '.') { // Check if it's a decimal number if (match[ndx] !== '.') { // Handle 0.5 and .5 v = assign(match[ndx++], s); } ndx++; // Check for decimal places if (ndx + 1 === match.length || match[ndx + 1] === '(' && match[ndx + 3] === ')' || match[ndx + 1] === "'" && match[ndx + 3] === "'") { w = assign(match[ndx], s); y = C_TEN ** BigInt(match[ndx].length); ndx++; } // Check for repeating places if (match[ndx] === '(' && match[ndx + 2] === ')' || match[ndx] === "'" && match[ndx + 2] === "'") { x = assign(match[ndx + 1], s); z = C_TEN ** BigInt(match[ndx + 1].length) - C_ONE; ndx+= 3; } } else if (match[ndx + 1] === '/' || match[ndx + 1] === ':') { // Check for a simple fraction "123/456" or "123:456" w = assign(match[ndx], s); y = assign(match[ndx + 2], C_ONE); ndx+= 3; } else if (match[ndx + 3] === '/' && match[ndx + 1] === ' ') { // Check for a complex fraction "123 1/2" v = assign(match[ndx], s); w = assign(match[ndx + 2], s); y = assign(match[ndx + 4], C_ONE); ndx+= 5; } if (match.length <= ndx) { // Check for more tokens on the stack d = y * z; s = /* void */ n = x + d * v + z * w; } else { throw Fraction['InvalidParameter']; } } else { throw Fraction['InvalidParameter']; } if (d === C_ZERO) { throw Fraction['DivisionByZero']; } P["s"] = s < C_ZERO ? -C_ONE : C_ONE; P["n"] = n < C_ZERO ? -n : n; P["d"] = d < C_ZERO ? -d : d; }; function modpow(b, e, m) { let r = C_ONE; for (; e > C_ZERO; b = (b * b) % m, e >>= C_ONE) { if (e & C_ONE) { r = (r * b) % m; } } return r; } function cycleLen(n, d) { for (; d % C_TWO === C_ZERO; d/= C_TWO) { } for (; d % C_FIVE === C_ZERO; d/= C_FIVE) { } if (d === C_ONE) // Catch non-cyclic numbers return C_ZERO; // If we would like to compute really large numbers quicker, we could make use of Fermat's little theorem: // 10^(d-1) % d == 1 // However, we don't need such large numbers and MAX_CYCLE_LEN should be the capstone, // as we want to translate the numbers to strings. let rem = C_TEN % d; let t = 1; for (; rem !== C_ONE; t++) { rem = rem * C_TEN % d; if (t > MAX_CYCLE_LEN) return C_ZERO; // Returning 0 here means that we don't print it as a cyclic number. It's likely that the answer is `d-1` } return BigInt(t); } function cycleStart(n, d, len) { let rem1 = C_ONE; let rem2 = modpow(C_TEN, len, d); for (let t = 0; t < 300; t++) { // s < ~log10(Number.MAX_VALUE) // Solve 10^s == 10^(s+t) (mod d) if (rem1 === rem2) return BigInt(t); rem1 = rem1 * C_TEN % d; rem2 = rem2 * C_TEN % d; } return 0; } function gcd(a, b) { if (!a) return b; if (!b) return a; while (1) { a%= b; if (!a) return b; b%= a; if (!b) return a; } } /** * Module constructor * * @constructor * @param {number|Fraction=} a * @param {number=} b */ function Fraction(a, b) { parse(a, b); if (this instanceof Fraction) { a = gcd(P["d"], P["n"]); // Abuse a this["s"] = P["s"]; this["n"] = P["n"] / a; this["d"] = P["d"] / a; } else { return newFraction(P['s'] * P['n'], P['d']); } } Fraction['DivisionByZero'] = new Error("Division by Zero"); Fraction['InvalidParameter'] = new Error("Invalid argument"); Fraction['NonIntegerParameter'] = new Error("Parameters must be integer"); Fraction.prototype = { "s": C_ONE, "n": C_ZERO, "d": C_ONE, /** * Calculates the absolute value * * Ex: new Fraction(-4).abs() => 4 **/ "abs": function() { return newFraction(this["n"], this["d"]); }, /** * Inverts the sign of the current fraction * * Ex: new Fraction(-4).neg() => 4 **/ "neg": function() { return newFraction(-this["s"] * this["n"], this["d"]); }, /** * Adds two rational numbers * * Ex: new Fraction({n: 2, d: 3}).add("14.9") => 467 / 30 **/ "add": function(a, b) { parse(a, b); return newFraction( this["s"] * this["n"] * P["d"] + P["s"] * this["d"] * P["n"], this["d"] * P["d"] ); }, /** * Subtracts two rational numbers * * Ex: new Fraction({n: 2, d: 3}).add("14.9") => -427 / 30 **/ "sub": function(a, b) { parse(a, b); return newFraction( this["s"] * this["n"] * P["d"] - P["s"] * this["d"] * P["n"], this["d"] * P["d"] ); }, /** * Multiplies two rational numbers * * Ex: new Fraction("-17.(345)").mul(3) => 5776 / 111 **/ "mul": function(a, b) { parse(a, b); return newFraction( this["s"] * P["s"] * this["n"] * P["n"], this["d"] * P["d"] ); }, /** * Divides two rational numbers * * Ex: new Fraction("-17.(345)").inverse().div(3) **/ "div": function(a, b) { parse(a, b); return newFraction( this["s"] * P["s"] * this["n"] * P["d"], this["d"] * P["n"] ); }, /** * Clones the actual object * * Ex: new Fraction("-17.(345)").clone() **/ "clone": function() { return newFraction(this['s'] * this['n'], this['d']); }, /** * Calculates the modulo of two rational numbers - a more precise fmod * * Ex: new Fraction('4.(3)').mod([7, 8]) => (13/3) % (7/8) = (5/6) **/ "mod": function(a, b) { if (a === undefined) { return newFraction(this["s"] * this["n"] % this["d"], C_ONE); } parse(a, b); if (0 === P["n"] && 0 === this["d"]) { throw Fraction['DivisionByZero']; } /* * First silly attempt, kinda slow * return that["sub"]({ "n": num["n"] * Math.floor((this.n / this.d) / (num.n / num.d)), "d": num["d"], "s": this["s"] });*/ /* * New attempt: a1 / b1 = a2 / b2 * q + r * => b2 * a1 = a2 * b1 * q + b1 * b2 * r * => (b2 * a1 % a2 * b1) / (b1 * b2) */ return newFraction( this["s"] * (P["d"] * this["n"]) % (P["n"] * this["d"]), P["d"] * this["d"] ); }, /** * Calculates the fractional gcd of two rational numbers * * Ex: new Fraction(5,8).gcd(3,7) => 1/56 */ "gcd": function(a, b) { parse(a, b); // gcd(a / b, c / d) = gcd(a, c) / lcm(b, d) return newFraction(gcd(P["n"], this["n"]) * gcd(P["d"], this["d"]), P["d"] * this["d"]); }, /** * Calculates the fractional lcm of two rational numbers * * Ex: new Fraction(5,8).lcm(3,7) => 15 */ "lcm": function(a, b) { parse(a, b); // lcm(a / b, c / d) = lcm(a, c) / gcd(b, d) if (P["n"] === C_ZERO && this["n"] === C_ZERO) { return newFraction(C_ZERO, C_ONE); } return newFraction(P["n"] * this["n"], gcd(P["n"], this["n"]) * gcd(P["d"], this["d"])); }, /** * Gets the inverse of the fraction, means numerator and denominator are exchanged * * Ex: new Fraction([-3, 4]).inverse() => -4 / 3 **/ "inverse": function() { return newFraction(this["s"] * this["d"], this["n"]); }, /** * Calculates the fraction to some integer exponent * * Ex: new Fraction(-1,2).pow(-3) => -8 */ "pow": function(a, b) { parse(a, b); // Trivial case when exp is an integer if (P['d'] === C_ONE) { if (P['s'] < C_ZERO) { return newFraction((this['s'] * this["d"]) ** P['n'], this["n"] ** P['n']); } else { return newFraction((this['s'] * this["n"]) ** P['n'], this["d"] ** P['n']); } } // Negative roots become complex // (-a/b)^(c/d) = x // <=> (-1)^(c/d) * (a/b)^(c/d) = x // <=> (cos(pi) + i*sin(pi))^(c/d) * (a/b)^(c/d) = x // <=> (cos(c*pi/d) + i*sin(c*pi/d)) * (a/b)^(c/d) = x # DeMoivre's formula // From which follows that only for c=0 the root is non-complex if (this['s'] < C_ZERO) return null; // Now prime factor n and d let N = factorize(this['n']); let D = factorize(this['d']); // Exponentiate and take root for n and d individually let n = C_ONE; let d = C_ONE; for (let k in N) { if (k === '1') continue; if (k === '0') { n = C_ZERO; break; } N[k]*= P['n']; if (N[k] % P['d'] === C_ZERO) { N[k]/= P['d']; } else return null; n*= BigInt(k) ** N[k]; } for (let k in D) { if (k === '1') continue; D[k]*= P['n']; if (D[k] % P['d'] === C_ZERO) { D[k]/= P['d']; } else return null; d*= BigInt(k) ** D[k]; } if (P['s'] < C_ZERO) { return newFraction(d, n); } return newFraction(n, d); }, /** * Check if two rational numbers are the same * * Ex: new Fraction(19.6).equals([98, 5]); **/ "equals": function(a, b) { parse(a, b); return this["s"] * this["n"] * P["d"] === P["s"] * P["n"] * this["d"]; // Same as compare() === 0 }, /** * Check if two rational numbers are the same * * Ex: new Fraction(19.6).equals([98, 5]); **/ "compare": function(a, b) { parse(a, b); let t = (this["s"] * this["n"] * P["d"] - P["s"] * P["n"] * this["d"]); return (C_ZERO < t) - (t < C_ZERO); }, /** * Calculates the ceil of a rational number * * Ex: new Fraction('4.(3)').ceil() => (5 / 1) **/ "ceil": function(places) { places = C_TEN ** BigInt(places || 0); return newFraction(this["s"] * places * this["n"] / this["d"] + (places * this["n"] % this["d"] > C_ZERO && this["s"] >= C_ZERO ? C_ONE : C_ZERO), places); }, /** * Calculates the floor of a rational number * * Ex: new Fraction('4.(3)').floor() => (4 / 1) **/ "floor": function(places) { places = C_TEN ** BigInt(places || 0); return newFraction(this["s"] * places * this["n"] / this["d"] - (places * this["n"] % this["d"] > C_ZERO && this["s"] < C_ZERO ? C_ONE : C_ZERO), places); }, /** * Rounds a rational numbers * * Ex: new Fraction('4.(3)').round() => (4 / 1) **/ "round": function(places) { places = C_TEN ** BigInt(places || 0); /* Derivation: s >= 0: round(n / d) = trunc(n / d) + (n % d) / d >= 0.5 ? 1 : 0 = trunc(n / d) + 2(n % d) >= d ? 1 : 0 s < 0: round(n / d) =-trunc(n / d) - (n % d) / d > 0.5 ? 1 : 0 =-trunc(n / d) - 2(n % d) > d ? 1 : 0 =>: round(s * n / d) = s * trunc(n / d) + s * (C + 2(n % d) > d ? 1 : 0) where C = s >= 0 ? 1 : 0, to fix the >= for the positve case. */ return newFraction(this["s"] * places * this["n"] / this["d"] + this["s"] * ((this["s"] >= C_ZERO ? C_ONE : C_ZERO) + C_TWO * (places * this["n"] % this["d"]) > this["d"] ? C_ONE : C_ZERO), places); }, /** * Check if two rational numbers are divisible * * Ex: new Fraction(19.6).divisible(1.5); */ "divisible": function(a, b) { parse(a, b); return !(!(P["n"] * this["d"]) || ((this["n"] * P["d"]) % (P["n"] * this["d"]))); }, /** * Returns a decimal representation of the fraction * * Ex: new Fraction("100.'91823'").valueOf() => 100.91823918239183 **/ 'valueOf': function() { // Best we can do so far return Number(this["s"] * this["n"]) / Number(this["d"]); }, /** * Creates a string representation of a fraction with all digits * * Ex: new Fraction("100.'91823'").toString() => "100.(91823)" **/ 'toString': function(dec) { let N = this["n"]; let D = this["d"]; dec = dec || 15; // 15 = decimal places when no repitation let cycLen = cycleLen(N, D); // Cycle length let cycOff = cycleStart(N, D, cycLen); // Cycle start let str = this['s'] < C_ZERO ? "-" : ""; // Append integer part str+= N / D; N%= D; N*= C_TEN; if (N) str+= "."; if (cycLen) { for (let i = cycOff; i--;) { str+= N / D; N%= D; N*= C_TEN; } str+= "("; for (let i = cycLen; i--;) { str+= N / D; N%= D; N*= C_TEN; } str+= ")"; } else { for (let i = dec; N && i--;) { str+= N / D; N%= D; N*= C_TEN; } } return str; }, /** * Returns a string-fraction representation of a Fraction object * * Ex: new Fraction("1.'3'").toFraction() => "4 1/3" **/ 'toFraction': function(excludeWhole) { let n = this["n"]; let d = this["d"]; let str = this['s'] < C_ZERO ? "-" : ""; if (d === C_ONE) { str+= n; } else { let whole = n / d; if (excludeWhole && whole > C_ZERO) { str+= whole; str+= " "; n%= d; } str+= n; str+= '/'; str+= d; } return str; }, /** * Returns a latex representation of a Fraction object * * Ex: new Fraction("1.'3'").toLatex() => "\frac{4}{3}" **/ 'toLatex': function(excludeWhole) { let n = this["n"]; let d = this["d"]; let str = this['s'] < C_ZERO ? "-" : ""; if (d === C_ONE) { str+= n; } else { let whole = n / d; if (excludeWhole && whole > C_ZERO) { str+= whole; n%= d; } str+= "\\frac{"; str+= n; str+= '}{'; str+= d; str+= '}'; } return str; }, /** * Returns an array of continued fraction elements * * Ex: new Fraction("7/8").toContinued() => [0,1,7] */ 'toContinued': function() { let a = this['n']; let b = this['d']; let res = []; do { res.push(a / b); let t = a % b; a = b; b = t; } while (a !== C_ONE); return res; }, "simplify": function(eps) { eps = eps || 0.001; const thisABS = this['abs'](); const cont = thisABS['toContinued'](); for (let i = 1; i < cont.length; i++) { let s = newFraction(cont[i - 1], C_ONE); for (let k = i - 2; k >= 0; k--) { s = s['inverse']()['add'](cont[k]); } if (s['sub'](thisABS)['abs']().valueOf() < eps) { return s['mul'](this['s']); } } return this; } }; if (typeof define === "function" && define["amd"]) { define([], function() { return Fraction; }); } else if (typeof exports === "object") { Object.defineProperty(exports, "__esModule", { 'value': true }); Fraction['default'] = Fraction; Fraction['Fraction'] = Fraction; module['exports'] = Fraction; } else { root['Fraction'] = Fraction; } })(this);