git.r.bdr.sh - rbdr/dotfiles/blob

   1 // Parts of implementation taken from es6-shim project
   2 // See: https://github.com/paulmillr/es6-shim/blob/master/es6-shim.js
   3
   4 'use strict';
   5
   6 var expm1 = require('../expm1')
   7
   8   , abs = Math.abs, exp = Math.exp, e = Math.E;
   9
  10 module.exports = function (x) {
  11         if (isNaN(x)) return NaN;
  12         x = Number(x);
  13         if (x === 0) return x;
  14         if (!isFinite(x)) return x;
  15         if (abs(x) < 1) return (expm1(x) - expm1(-x)) / 2;
  16         return (exp(x - 1) - exp(-x - 1)) * e / 2;
  17 };