1 /* $NetBSD: ccos.c,v 1.1 2007/08/20 16:01:32 drochner Exp $ */
2 
3 /*-
4  * Copyright (c) 2007 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software written by Stephen L. Moshier.
8  * It is redistributed by the NetBSD Foundation by permission of the author.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  *
31  * imported and modified include for newlib 2010/10/03
32  * Marco Atzeri <marco_atzeri@yahoo.it>
33  */
34 
35 /*
36 FUNCTION
37         <<ccos>>, <<ccosf>>---complex cosine
38 
39 INDEX
40         ccos
41 INDEX
42         ccosf
43 
44 SYNOPSIS
45        #include <complex.h>
46        double complex ccos(double complex <[z]>);
47        float complex ccosf(float complex <[z]>);
48 
49 
50 DESCRIPTION
51         These functions compute the complex cosine of <[z]>.
52 
53         <<ccosf>> is identical to <<ccos>>, except that it performs
54         its calculations on <<floats complex>>.
55 
56 RETURNS
57         These functions return the complex cosine value.
58 
59 PORTABILITY
60         <<ccos>> and <<ccosf>> are ISO C99
61 
62 QUICKREF
63         <<ccos>> and <<ccosf>> are ISO C99
64 
65 */
66 
67 
68 #include <complex.h>
69 #include <math.h>
70 #include "cephes_subr.h"
71 
72 double complex
ccos(double complex z)73 ccos(double complex z)
74 {
75 	double complex w;
76 	double ch, sh;
77 
78 	_cchsh(cimag(z), &ch, &sh);
79 	w = cos(creal(z)) * ch - (sin(creal(z)) * sh) * (double complex) I;
80 	return w;
81 }
82