gonzui

    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: }