1 /*	$OpenBSD: s_csinh.c,v 1.6 2013/07/03 04:46:36 espie 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 /*							csinh
19  *
20  *	Complex hyperbolic sine
21  *
22  *
23  *
24  * SYNOPSIS:
25  *
26  * double complex csinh();
27  * double complex z, w;
28  *
29  * w = csinh (z);
30  *
31  * DESCRIPTION:
32  *
33  * csinh z = (cexp(z) - cexp(-z))/2
34  *         = sinh x * cos y  +  i cosh x * sin y .
35  *
36  * ACCURACY:
37  *
38  *                      Relative error:
39  * arithmetic   domain     # trials      peak         rms
40  *    IEEE      -10,+10     30000       3.1e-16     8.2e-17
41  *
42  */
43 
44 #include <complex.h>
45 #include <float.h>
46 #include <math.h>
47 
48 double complex
49 csinh(double complex z)
50 {
51 	double complex w;
52 	double x, y;
53 
54 	x = creal(z);
55 	y = cimag(z);
56 	w = sinh (x) * cos (y)  +  (cosh (x) * sin (y)) * I;
57 	return (w);
58 }
59 
60 #if	LDBL_MANT_DIG == DBL_MANT_DIG
61 __strong_alias(csinhl, csinh);
62 #endif	/* LDBL_MANT_DIG == DBL_MANT_DIG */
63