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 }
68