mathjs/lib/type/fraction/function/fraction.js

Math.js is an extensive math library for JavaScript and Node.js. It features a flexible expression parser and offers an integrated solution to work with numbers, big numbers, complex numbers, units, and matrices.

'use strict';

var deepMap = require('../../../utils/collection/deepMap');

function factory (type, config, load, typed) {
  /**
   * Create a fraction convert a value to a fraction.
   *
   * Syntax:
   *     math.fraction(numerator, denominator)
   *     math.fraction({n: numerator, d: denominator})
   *     math.fraction(matrix: Array | Matrix)         Turn all matrix entries
   *                                                   into fractions
   *
   * Examples:
   *
   *     math.fraction(1, 3);
   *     math.fraction('2/3');
   *     math.fraction({n: 2, d: 3});
   *     math.fraction([0.2, 0.25, 1.25]);
   *
   * See also:
   *
   *    bignumber, number, string, unit
   *
   * @param {number | string | Fraction | BigNumber | Array | Matrix} [args]
   *            Arguments specifying the numerator and denominator of
   *            the fraction
   * @return {Fraction | Array | Matrix} Returns a fraction
   */
  var fraction = typed('fraction', {
    'number': function (x) {
      if (!isFinite(x) || isNaN(x)) {
        throw new Error(x + ' cannot be represented as a fraction');
      }

      return new type.Fraction(x);
    },

    'string': function (x) {
      return new type.Fraction(x);
    },

    'number, number': function (numerator, denominator) {
      return new type.Fraction(numerator, denominator);
    },

    'BigNumber': function (x) {
      return new type.Fraction(x.toString());
    },

    'Fraction': function (x) {
      return x; // fractions are immutable
    },

    'Object': function (x) {
      return new type.Fraction(x);
    },

    'Array | Matrix': function (x) {
      return deepMap(x, fraction);
    }
  });

  return fraction;
}

exports.name = 'fraction';
exports.factory = factory;