xref: /openbsd-src/lib/libm/src/s_csinh.c (revision 4c1e55dc91edd6e69ccc60ce855900fbc12cf34f)
1 /*	$OpenBSD: s_csinh.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 /*							csinh
21  *
22  *	Complex hyperbolic sine
23  *
24  *
25  *
26  * SYNOPSIS:
27  *
28  * double complex csinh();
29  * double complex z, w;
30  *
31  * w = csinh (z);
32  *
33  * DESCRIPTION:
34  *
35  * csinh z = (cexp(z) - cexp(-z))/2
36  *         = sinh x * cos y  +  i cosh x * sin y .
37  *
38  * ACCURACY:
39  *
40  *                      Relative error:
41  * arithmetic   domain     # trials      peak         rms
42  *    IEEE      -10,+10     30000       3.1e-16     8.2e-17
43  *
44  */
45 
46 #include <sys/cdefs.h>
47 #include <complex.h>
48 #include <float.h>
49 #include <math.h>
50 
51 double complex
52 csinh(double complex z)
53 {
54 	double complex w;
55 	double x, y;
56 
57 	x = creal(z);
58 	y = cimag(z);
59 	w = sinh (x) * cos (y)  +  (cosh (x) * sin (y)) * I;
60 	return (w);
61 }
62 
63 #if	LDBL_MANT_DIG == 53
64 #ifdef	lint
65 /* PROTOLIB1 */
66 long double complex csinhl(long double complex);
67 #else	/* lint */
68 __weak_alias(csinhl, csinh);
69 #endif	/* lint */
70 #endif	/* LDBL_MANT_DIG == 53 */
71