node_modules/locutus/php/math/log1p.js


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28

'use strict';

module.exports = function log1p(x) {
  //  discuss at: http://locutus.io/php/log1p/
  // original by: Brett Zamir (http://brett-zamir.me)
  // improved by: Robert Eisele (http://www.xarg.org/)
  //      note 1: Precision 'n' can be adjusted as desired
  //   example 1: log1p(1e-15)
  //   returns 1: 9.999999999999995e-16

  var ret = 0;
  // degree of precision
  var n = 50;

  if (x <= -1) {
    // JavaScript style would be to return Number.NEGATIVE_INFINITY
    return '-INF';
  }
  if (x < 0 || x > 1) {
    return Math.log(1 + x);
  }
  for (var i = 1; i < n; i++) {
    ret += Math.pow(-x, i) / i;
  }

  return -ret;
};
//# sourceMappingURL=log1p.js.map