1 /* $OpenBSD: s_cexp.c,v 1.7 2016/09/12 19:47:02 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 /* cexp()
19 *
20 * Complex exponential function
21 *
22 *
23 *
24 * SYNOPSIS:
25 *
26 * double complex cexp ();
27 * double complex z, w;
28 *
29 * w = cexp (z);
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 * DEC -10,+10 8700 3.7e-17 1.1e-17
52 * IEEE -10,+10 30000 3.0e-16 8.7e-17
53 *
54 */
55
56 #include <complex.h>
57 #include <float.h>
58 #include <math.h>
59
60 double complex
cexp(double complex z)61 cexp(double complex z)
62 {
63 double complex w;
64 double r, x, y;
65
66 x = creal (z);
67 y = cimag (z);
68 r = exp (x);
69 w = r * cos (y) + r * sin (y) * I;
70 return (w);
71 }
72 DEF_STD(cexp);
73 LDBL_MAYBE_UNUSED_CLONE(cexp);
74