1 /* $OpenBSD: s_cacosf.c,v 1.2 2011/07/20 19:28:33 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 /* cacosf()
19 *
20 * Complex circular arc cosine
21 *
22 *
23 *
24 * SYNOPSIS:
25 *
26 * void cacosf();
27 * cmplxf z, w;
28 *
29 * cacosf( &z, &w );
30 *
31 *
32 *
33 * DESCRIPTION:
34 *
35 *
36 * w = arccos z = PI/2 - arcsin z.
37 *
38 *
39 *
40 *
41 * ACCURACY:
42 *
43 * Relative error:
44 * arithmetic domain # trials peak rms
45 * IEEE -10,+10 30000 9.2e-6 1.2e-6
46 *
47 */
48
49 #include <complex.h>
50 #include <math.h>
51
52 float complex
cacosf(float complex z)53 cacosf(float complex z)
54 {
55 float complex w;
56
57 w = casinf( z );
58 w = ((float)M_PI_2 - crealf (w)) - cimagf (w) * I;
59 return (w);
60 }
61