xref: /openbsd/lib/libm/src/s_cacosh.c (revision cca36db2)
1 /*	$OpenBSD: s_cacosh.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 /*							cacosh
21  *
22  *	Complex inverse hyperbolic cosine
23  *
24  *
25  *
26  * SYNOPSIS:
27  *
28  * double complex cacosh();
29  * double complex z, w;
30  *
31  * w = cacosh (z);
32  *
33  *
34  *
35  * DESCRIPTION:
36  *
37  * acosh z = i acos z .
38  *
39  * ACCURACY:
40  *
41  *                      Relative error:
42  * arithmetic   domain     # trials      peak         rms
43  *    IEEE      -10,+10     30000       1.6e-14     2.1e-15
44  *
45  */
46 
47 #include <sys/cdefs.h>
48 #include <complex.h>
49 #include <float.h>
50 #include <math.h>
51 
52 double complex
53 cacosh(double complex z)
54 {
55 	double complex w;
56 
57 	w = I * cacos (z);
58 	return (w);
59 }
60 
61 #if	LDBL_MANT_DIG == 53
62 #ifdef	lint
63 /* PROTOLIB1 */
64 long double complex cacoshl(long double complex);
65 #else	/* lint */
66 __weak_alias(cacoshl, cacosh);
67 #endif	/* lint */
68 #endif	/* LDBL_MANT_DIG == 53 */
69