1 /*
2 Copyright (c) 2007 The NetBSD Foundation, Inc.
3 All rights reserved.
4
5 Redistribution and use in source and binary forms, with or without
6 modification, are permitted provided that the following conditions
7 are met:
8 1. Redistributions of source code must retain the above copyright
9 notice, this list of conditions and the following disclaimer.
10 2. Redistributions in binary form must reproduce the above copyright
11 notice, this list of conditions and the following disclaimer in the
12 documentation and/or other materials provided with the distribution.
13
14 THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
15 AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
16 TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17 PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
18 BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
19 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
20 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
21 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
22 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
23 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
24 POSSIBILITY OF SUCH DAMAGE.
25 */
26 /* $NetBSD: carg.c,v 1.1 2007/08/20 16:01:31 drochner Exp $ */
27
28 /*
29 * Written by Matthias Drochner <drochner@NetBSD.org>.
30 * Public domain.
31 *
32 * imported and modified include for newlib 2010/10/03
33 * Marco Atzeri <marco_atzeri@yahoo.it>
34 */
35
36 /*
37 FUNCTION
38 <<carg>>, <<cargf>>---argument (phase angle)
39
40 INDEX
41 carg
42 INDEX
43 cargf
44
45 SYNOPSIS
46 #include <complex.h>
47 double carg(double complex <[z]>);
48 float cargf(float complex <[z]>);
49
50
51 DESCRIPTION
52 These functions compute the argument (also called phase angle)
53 of <[z]>, with a branch cut along the negative real axis.
54
55 <<cargf>> is identical to <<carg>>, except that it performs
56 its calculations on <<floats complex>>.
57
58 RETURNS
59 @ifnottex
60 The carg functions return the value of the argument in the
61 interval [-pi, +pi]
62 @end ifnottex
63 @tex
64 The carg functions return the value of the argument in the
65 interval [$-\pi$, $+\pi$]
66 @end tex
67
68 PORTABILITY
69 <<carg>> and <<cargf>> are ISO C99
70
71 QUICKREF
72 <<carg>> and <<cargf>> are ISO C99
73
74 */
75
76 #include <complex.h>
77 #include <math.h>
78
79 double
carg(double complex z)80 carg(double complex z)
81 {
82
83 return atan2( cimag(z) , creal(z) );
84 }
85
