1 /* $OpenBSD: s_cacoshl.c,v 1.1 2011/07/08 19:25:31 martynas Exp $ */
2
3 /*
4 * Copyright (c) 2008 Stephen L. Moshier <steve@moshier.net>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 /* cacoshl
20 *
21 * Complex inverse hyperbolic cosine
22 *
23 *
24 *
25 * SYNOPSIS:
26 *
27 * long double complex cacoshl();
28 * long double complex z, w;
29 *
30 * w = cacoshl (z);
31 *
32 *
33 *
34 * DESCRIPTION:
35 *
36 * acosh z = i acos z .
37 *
38 * ACCURACY:
39 *
40 * Relative error:
41 * arithmetic domain # trials peak rms
42 * IEEE -10,+10 30000 1.6e-14 2.1e-15
43 *
44 */
45
46 #include <complex.h>
47 #include <math.h>
48
49 long double complex
cacoshl(long double complex z)50 cacoshl(long double complex z)
51 {
52 long double complex w;
53 long double rx, ry;
54
55 w = cacosl (z);
56 rx = creall (w);
57 ry = cimagl (w);
58 if (isnan(rx) && isnan(ry))
59 return (CMPLXL(ry, rx));
60 if (isnan(rx))
61 return (CMPLXL(fabsl(ry), rx));
62 if (isnan(ry))
63 return (CMPLXL(ry, ry));
64 return (CMPLXL(fabsl(ry), copysignl(rx, cimagl(z))));
65 }
66