compiler/stdc/math/s_ctanhl.c

   1 /*      $OpenBSD: s_ctanhl.c,v 1.2 2011/07/20 19:28:33 martynas Exp $   */
   2
   3 /*
   4  * Copyright (c) 2008 Stephen L. Moshier <steve@moshier.net>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 /*                                                      ctanhl
  20  *
  21  *      Complex hyperbolic tangent
  22  *
  23  *
  24  *
  25  * SYNOPSIS:
  26  *
  27  * long double complex ctanhl();
  28  * long double complex z, w;
  29  *
  30  * w = ctanhl (z);
  31  *
  32  *
  33  *
  34  * DESCRIPTION:
  35  *
  36  * tanh z = (sinh 2x  +  i sin 2y) / (cosh 2x + cos 2y) .
  37  *
  38  * ACCURACY:
  39  *
  40  *                      Relative error:
  41  * arithmetic   domain     # trials      peak         rms
  42  *    IEEE      -10,+10     30000       1.7e-14     2.4e-16
  43  *
  44  */
  45
  46 #include <complex.h>
  47 #include "math.h"
  48
  49 long double complex
  50 ctanhl(long double complex z)
  51 {
  52         long double complex w;
  53         long double x, y, d;
  54
  55         x = creall(z);
  56         y = cimagl(z);
  57         d = coshl(2.0L * x) + cosl(2.0L * y);
  58         w = sinhl(2.0L * x) / d + (sinl(2.0L * y) / d) * I;
  59         return (w);
  60 }