gonzui

    1: /*      $OpenBSD: s_cexpf.c,v 1.2 2010/07/18 18:42:26 guenther 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: /*                                                      cexpf()
   19:  *
   20:  *      Complex exponential function
   21:  *
   22:  *
   23:  *
   24:  * SYNOPSIS:
   25:  *
   26:  * void cexpf();
   27:  * cmplxf z, w;
   28:  *
   29:  * cexpf( &z, &w );
   30:  *
   31:  *
   32:  *
   33:  * DESCRIPTION:
   34:  *
   35:  * Returns the exponential of the complex argument z
   36:  * into the complex result w.
   37:  *
   38:  * If
   39:  *     z = x + iy,
   40:  *     r = exp(x),
   41:  *
   42:  * then
   43:  *
   44:  *     w = r cos y + i r sin y.
   45:  *
   46:  *
   47:  * ACCURACY:
   48:  *
   49:  *                      Relative error:
   50:  * arithmetic   domain     # trials      peak         rms
   51:  *    IEEE      -10,+10     30000       1.4e-7      4.5e-8
   52:  *
   53:  */
   54: 
   55: #include <complex.h>
   56: #include <math.h>
   57: 
   58: float complex
   59: cexpf(float complex z)
   60: {
   61:         float complex w;
   62:         float r;
   63: 
   64:         r = expf( crealf(z) );
   65:         w = r * cosf( cimagf(z) ) +  r * sinf( cimagf(z) ) * I;
   66:         return (w);
   67: }