Last active
November 28, 2016 03:15
-
-
Save leontastic/8e42bbfb0d97b8f4f5dc to your computer and use it in GitHub Desktop.
Revisions
-
leontastic revised this gist
Sep 8, 2015 . 1 changed file with 41 additions and 4 deletions.There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode charactersOriginal file line number Diff line number Diff line change @@ -18,6 +18,9 @@ subtract([n|Number|Fraction]) => [Fraction] returns fraction minus n multiply([n|Number|Fraction]) => [Fraction] returns fraction multiplied by n divide([n|Number|Fraction]) => [Fraction] returns fraction divided by n mod([n|Number|Fraction]) => [Fraction] returns fraction mod n lt([n|Number|Fraction]) => [Boolean] returns true if fraction is less than n gt([n|Number|Fraction]) => [Boolean] returns true if fraction is greater than n toNumber() => [Number] returns the native Number representation of the fraction */ @@ -65,7 +68,7 @@ class Fraction { // add a number or fraction to this fraction add(n) { if (!(n instanceof Fraction)) n = new Fraction(n); let output = new Fraction(this); // copy this fraction let multiple = Fraction.lcm(output.denominator, n.denominator); @@ -77,7 +80,7 @@ class Fraction { // subtract a number or fraction from this fraction subtract(n) { if (!(n instanceof Fraction)) n = new Fraction(n); let output = new Fraction(this); // copy this fraction let multiple = Fraction.lcm(output.denominator, n.denominator); @@ -89,7 +92,7 @@ class Fraction { // multiply this fraction by a number or fraction multiply(n) { if (!(n instanceof Fraction)) n = new Fraction(n); let output = new Fraction(this); // copy this fraction output.numerator *= n.numerator; @@ -100,7 +103,7 @@ class Fraction { // divide this fraction by a number or fraction divide(n) { if (!(n instanceof Fraction)) n = new Fraction(n); let output = new Fraction(this); // copy this fraction output.numerator *= n.denominator; @@ -109,6 +112,40 @@ class Fraction { return output; } // mod this fraction by a number or fraction (same as JS modulo operator '%') mod(n) { if (!(n instanceof Fraction)) n = new Fraction(n); let output = new Fraction(this); // copy this fraction if (output.gt(0)) { while (output.gt(n)) { output = output.subtract(n); } } else { while (output.lt(n)) { output = output.add(n); } } return output.toNumber(); } // check if this fraction is less than a number or fraction lt(n) { if (!(n instanceof Fraction)) n = new Fraction(n); let output = new Fraction(this); // copy this fraction return output.toNumber() < n.toNumber(); } // check if this fraction is greater than a number or fraction gt(n) { if (!(n instanceof Fraction)) n = new Fraction(n); let output = new Fraction(this); // copy this fraction return output.toNumber() > n.toNumber(); } // get Number representation of fraction toNumber() { return this.numerator / this.denominator; -
Sep 5, 2015 . 1 changed file with 1 addition and 1 deletion.There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode charactersOriginal file line number Diff line number Diff line change @@ -18,7 +18,7 @@ subtract([n|Number|Fraction]) => [Fraction] returns fraction minus n multiply([n|Number|Fraction]) => [Fraction] returns fraction multiplied by n divide([n|Number|Fraction]) => [Fraction] returns fraction divided by n toNumber() => [Number] returns the native Number representation of the fraction */ class Fraction { -
Sep 5, 2015 .There are no files selected for viewing
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode charactersOriginal file line number Diff line number Diff line change @@ -0,0 +1,116 @@ /* Fraction: an ES6 class to preserve decimal precision in rational number arithmetic Notes: - reliably preserves decimal precision for floats that can be represented in decimal with 16 decimal places or less - for decimals with more than 16 decimal places, precision is preserved up to 16 decimal places CONSTRUCTOR: constructor([a|Number|Fraction]) => [Fraction]: returns a Fraction from a number STATIC METHODS: gcd([a|Number], [b|Number]) => [Number] recursively finds greatest common denominator of a and b lcm([a|Number], [b|Number]) => [Number] finds the lowest common multiple of a and b (depends on gcd(a,b)) INSTANCE METHODS: reduce() => [] reduces the fraction to simplest terms (used internally to always keep simplest terms) add([n|Number|Fraction]) => [Fraction] returns fraction plus n subtract([n|Number|Fraction]) => [Fraction] returns fraction minus n multiply([n|Number|Fraction]) => [Fraction] returns fraction multiplied by n divide([n|Number|Fraction]) => [Fraction] returns fraction divided by n toNumber() => [] returns the native Number representation of the fraction */ class Fraction { constructor(num) { if (typeof num === 'number') { this.numerator = num; this.denominator = 1; } else if (num instanceof Fraction) { this.numerator = num.numerator; this.denominator = num.denominator; } else { throw new Error('Invalid conversion to Fraction'); } // we always want the numerator to be an integer // convert float to integer via string manipulation // (since multiplication sometimes results in floating point errors) if (this.numerator % 1 !== 0) { let exp = (this.numerator + '').replace(/^-?\d*\.?|0+$/g, '').length; // count number of decimal places this.numerator = parseInt((this.numerator + '').replace('.', '')); // strip decimal point and parse as integer this.denominator = Math.pow(10, exp); } // new fractions should always be in lowest terms this.reduce(); } // GCD utility (recursive algorithm) static gcd(a, b) { return b ? Fraction.gcd(b, a % b) : a; } // LCM utility (depends on Fraction.gcd) static lcm(a, b) { return Math.abs(a * b) / Fraction.gcd(a, b); } // reduces fraction to simplest terms reduce() { let d = Fraction.gcd(this.numerator, this.denominator); this.numerator /= d; this.denominator /= d; } // add a number or fraction to this fraction add(n) { if (!n instanceof Fraction) n = new Fraction(n); let output = new Fraction(this); // copy this fraction let multiple = Fraction.lcm(output.denominator, n.denominator); output.numerator = output.numerator * (multiple / output.denominator) + n.numerator * (multiple / n.denominator); output.denominator = multiple; output.reduce(); return output; } // subtract a number or fraction from this fraction subtract(n) { if (!n instanceof Fraction) n = new Fraction(n); let output = new Fraction(this); // copy this fraction let multiple = Fraction.lcm(output.denominator, n.denominator); output.numerator = output.numerator * (multiple / output.denominator) - n.numerator * (multiple / n.denominator); output.denominator = multiple; output.reduce(); return output; } // multiply this fraction by a number or fraction multiply(n) { if (!n instanceof Fraction) n = new Fraction(n); let output = new Fraction(this); // copy this fraction output.numerator *= n.numerator; output.denominator *= n.denominator; output.reduce(); return output; } // divide this fraction by a number or fraction divide(n) { if (!n instanceof Fraction) n = new Fraction(n); let output = new Fraction(this); // copy this fraction output.numerator *= n.denominator; output.denominator *= n.numerator; output.reduce(); return output; } // get Number representation of fraction toNumber() { return this.numerator / this.denominator; } }