gonzui

    1: /*      $OpenBSD: s_cacos.c,v 1.2 2011/07/08 19:25:31 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: /* LINTLIBRARY */
   19: 
   20: /*                                                      cacos()
   21:  *
   22:  *      Complex circular arc cosine
   23:  *
   24:  *
   25:  *
   26:  * SYNOPSIS:
   27:  *
   28:  * double complex cacos();
   29:  * double complex z, w;
   30:  *
   31:  * w = cacos (z);
   32:  *
   33:  *
   34:  *
   35:  * DESCRIPTION:
   36:  *
   37:  *
   38:  * w = arccos z  =  PI/2 - arcsin z.
   39:  *
   40:  *
   41:  *
   42:  *
   43:  * ACCURACY:
   44:  *
   45:  *                      Relative error:
   46:  * arithmetic   domain     # trials      peak         rms
   47:  *    DEC       -10,+10      5200      1.6e-15      2.8e-16
   48:  *    IEEE      -10,+10     30000      1.8e-14      2.2e-15
   49:  */
   50: 
   51: #include <sys/cdefs.h>
   52: #include <complex.h>
   53: #include <float.h>
   54: #include <math.h>
   55: 
   56: double complex
   57: cacos(double complex z)
   58: {
   59:         double complex w;
   60: 
   61:         w = casin (z);
   62:         w = (M_PI_2 - creal (w)) - cimag (w) * I;
   63:         return (w);
   64: }
   65: 
   66: #if     LDBL_MANT_DIG == 53
   67: #ifdef  lint
   68: /* PROTOLIB1 */
   69: long double complex cacosl(long double complex);
   70: #else   /* lint */
   71: __weak_alias(cacosl, cacos);
   72: #endif  /* lint */
   73: #endif  /* LDBL_MANT_DIG == 53 */