mathjs/lib/function/arithmetic/divideScalar.js

'use strict';

module.exports = function (config) {
  var typed = require('typed-function');
  var Complex = require('../../type/Complex');

  /**
   * Divide two scalar values, `x / y`.
   * This function is meant for internal use: it is used by the public functions
   * `divide` and `inv`.
   *
   * This function does not support collections (Array or Matrix), and does
   * not validate the number of of inputs.
   *
   * @param  {Number | BigNumber | Boolean | Complex | Unit | null} x   Numerator
   * @param  {Number | BigNumber | Boolean | Complex | null} y          Denominator
   * @return {Number | BigNumber | Complex | Unit}                      Quotient, `x / y`
   * @private
   */
  var divideScalar = typed('divideScalar', {
    'number, number': function (x, y) {
      return x / y;
    },

    'Complex, Complex': _divideComplex,

    'BigNumber, BigNumber': function (x, y) {
      return x.div(y);
    },

    'Unit, number': function (x, y) {
      var res = x.clone();
      res.value = ((res.value === null) ? res._normalize(1) : res.value) / y;
      return res;
    }
  });

  /**
   * Divide two complex numbers. x / y or divide(x, y)
   * @param {Complex} x
   * @param {Complex} y
   * @return {Complex} res
   * @private
   */
  function _divideComplex (x, y) {
    var den = y.re * y.re + y.im * y.im;
    if (den != 0) {
      return new Complex(
          (x.re * y.re + x.im * y.im) / den,
          (x.im * y.re - x.re * y.im) / den
      );
    }
    else {
      // both y.re and y.im are zero
      return new Complex(
          (x.re != 0) ? (x.re / 0) : 0,
          (x.im != 0) ? (x.im / 0) : 0
      );
    }
  }

  return divideScalar;
};