fractional-arithmetic.js

A javascript library for doing fractional arithmetic.

Install

First do an npm install fractional-arithmetic.

Then, load the library into your code: var Fraction = require('fractional-arithmetic').Fraction;. You're good to go.

Example usage

var f = new Fraction( 7, 24 );
var g = Fraction( 11, 30 );
console.log( 'f=', f, 'g=', g );
console.log( 'f + g = ', f.plus(g) );
console.log( 'f - g = ', f.minus(g) );
console.log( 'f x g = ', f.times(g) );
console.log( 'f / g = ', f.dividedBy(g) );
console.log( 'latex f:', f.toLatex() );
console.log( 'number f:', f.toNumber() );

var pi= Fraction( 3.1415926 );
console.log( 'from decimal pi:', pi, pi.simplify() );

API

C'tors

Fraction(n,d) creates the fraction "n over d" (n and d must be integers)

Fraction(f) if f is fraction, creates a new fraction equal to fraction f

Fraction(d) if f is decimal number, creates a new fraction equal to decimal number d

Arithmetic methods (can be chained)

.add(f), .plus(f) both add fraction f to this fraction

.add(n,d), .plus(n,d) both add "n over d" to this fraction (n and d must be integers)

.minus(f) subtracts fraction f from this fraction

.minus(n,d) subtracts "n over d" from this fraction (n and d must be integers)

.times(f), .multiply(f) both multiply this fraction with fraction f

.times(n,d), .multiply(n,d) both multiply this fraction with fraction "n over d" (n and d must be integers)

.dividedBy(f), .div(f) both divide this fraction with fraction f

.dividedBy(n,d), .div(n,d) both divide this fraction with fraction "n over d" (n and d must be integers)

.inverse() returns the inverse of this fraction (flips numerator & denominator)

Conversion methods

.toString(), toS(), inspect() return a human-readable string of this fraction

.toLatex() returns the fraction as a LaTeX command string

.toMathML() returns the fraction as a MathML string

.toNumber() returns the fraction as a decimal number (divides numerator by denominator)

Helpers

If you need to use these you can import them separately, like so:

var gcd = require('fractional-arithmetic').gcd;

gcd(a,b) computes the Greatest Common Divisor of a and b

lcm(a,b) computes the Least Common Multiple of a and b

isInteger(n) true iff n is an integer

Exceptions

If an invalid fraction is specified, a NotAFractionError is thrown. For example, Fraction('foobar') will throw an error.

Grunt targets

These targets are available

Run jshint and nodeunit tests

grunt test

Build the minified version

grunt build

Run tests and build the minified version

grunt

Feedback

Send me an email at [email protected].