compiler/stdc/math/s_cacosf.c

   1 /*      $OpenBSD: s_cacosf.c,v 1.2 2011/07/20 19:28:33 martynas Exp $   */
   2 /*
   3  * Copyright (c) 2008 Stephen L. Moshier <steve@moshier.net>
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 /*                                                      cacosf()
  19  *
  20  *      Complex circular arc cosine
  21  *
  22  *
  23  *
  24  * SYNOPSIS:
  25  *
  26  * void cacosf();
  27  * cmplxf z, w;
  28  *
  29  * cacosf( &z, &w );
  30  *
  31  *
  32  *
  33  * DESCRIPTION:
  34  *
  35  *
  36  * w = arccos z  =  PI/2 - arcsin z.
  37  *
  38  *
  39  *
  40  *
  41  * ACCURACY:
  42  *
  43  *                      Relative error:
  44  * arithmetic   domain     # trials      peak         rms
  45  *    IEEE      -10,+10     30000       9.2e-6       1.2e-6
  46  *
  47  */
  48
  49 #include <complex.h>
  50 #include "math.h"
  51
  52 float complex
  53 cacosf(float complex z)
  54 {
  55         float complex w;
  56
  57         w = casinf( z );
  58         w = ((float)M_PI_2 - crealf (w)) - cimagf (w) * I;
  59         return (w);
  60 }