gonzui

    1: /*      $OpenBSD: s_ctanh.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: /*                                                      ctanh
   21:  *
   22:  *      Complex hyperbolic tangent
   23:  *
   24:  *
   25:  *
   26:  * SYNOPSIS:
   27:  *
   28:  * double complex ctanh();
   29:  * double complex z, w;
   30:  *
   31:  * w = ctanh (z);
   32:  *
   33:  *
   34:  *
   35:  * DESCRIPTION:
   36:  *
   37:  * tanh z = (sinh 2x  +  i sin 2y) / (cosh 2x + cos 2y) .
   38:  *
   39:  * ACCURACY:
   40:  *
   41:  *                      Relative error:
   42:  * arithmetic   domain     # trials      peak         rms
   43:  *    IEEE      -10,+10     30000       1.7e-14     2.4e-16
   44:  *
   45:  */
   46: 
   47: #include <sys/cdefs.h>
   48: #include <complex.h>
   49: #include <float.h>
   50: #include <math.h>
   51: 
   52: double complex
   53: ctanh(double complex z)
   54: {
   55:         double complex w;
   56:         double x, y, d;
   57: 
   58:         x = creal(z);
   59:         y = cimag(z);
   60:         d = cosh (2.0 * x) + cos (2.0 * y);
   61:         w = sinh (2.0 * x) / d  +  (sin (2.0 * y) / d) * I;
   62:         return (w);
   63: }
   64: 
   65: #if     LDBL_MANT_DIG == 53
   66: #ifdef  lint
   67: /* PROTOLIB1 */
   68: long double complex ctanhl(long double complex);
   69: #else   /* lint */
   70: __weak_alias(ctanhl, ctanh);
   71: #endif  /* lint */
   72: #endif  /* LDBL_MANT_DIG == 53 */