source: trunk/FACT++/erfa/src/rx.c@ 18348

Last change on this file since 18348 was 18348, checked in by tbretz, 9 years ago
File size: 4.2 KB
Line 
1#include "erfa.h"
2
3void eraRx(double phi, double r[3][3])
4/*
5** - - - - - -
6** e r a R x
7** - - - - - -
8**
9** Rotate an r-matrix about the x-axis.
10**
11** Given:
12** phi double angle (radians)
13**
14** Given and returned:
15** r double[3][3] r-matrix, rotated
16**
17** Notes:
18**
19** 1) Calling this function with positive phi incorporates in the
20** supplied r-matrix r an additional rotation, about the x-axis,
21** anticlockwise as seen looking towards the origin from positive x.
22**
23** 2) The additional rotation can be represented by this matrix:
24**
25** ( 1 0 0 )
26** ( )
27** ( 0 + cos(phi) + sin(phi) )
28** ( )
29** ( 0 - sin(phi) + cos(phi) )
30**
31** Copyright (C) 2013-2015, NumFOCUS Foundation.
32** Derived, with permission, from the SOFA library. See notes at end of file.
33*/
34{
35 double s, c, a10, a11, a12, a20, a21, a22;
36
37 s = sin(phi);
38 c = cos(phi);
39
40 a10 = c*r[1][0] + s*r[2][0];
41 a11 = c*r[1][1] + s*r[2][1];
42 a12 = c*r[1][2] + s*r[2][2];
43 a20 = - s*r[1][0] + c*r[2][0];
44 a21 = - s*r[1][1] + c*r[2][1];
45 a22 = - s*r[1][2] + c*r[2][2];
46
47 r[1][0] = a10;
48 r[1][1] = a11;
49 r[1][2] = a12;
50 r[2][0] = a20;
51 r[2][1] = a21;
52 r[2][2] = a22;
53
54 return;
55
56}
57/*----------------------------------------------------------------------
58**
59**
60** Copyright (C) 2013-2015, NumFOCUS Foundation.
61** All rights reserved.
62**
63** This library is derived, with permission, from the International
64** Astronomical Union's "Standards of Fundamental Astronomy" library,
65** available from http://www.iausofa.org.
66**
67** The ERFA version is intended to retain identical functionality to
68** the SOFA library, but made distinct through different function and
69** file names, as set out in the SOFA license conditions. The SOFA
70** original has a role as a reference standard for the IAU and IERS,
71** and consequently redistribution is permitted only in its unaltered
72** state. The ERFA version is not subject to this restriction and
73** therefore can be included in distributions which do not support the
74** concept of "read only" software.
75**
76** Although the intent is to replicate the SOFA API (other than
77** replacement of prefix names) and results (with the exception of
78** bugs; any that are discovered will be fixed), SOFA is not
79** responsible for any errors found in this version of the library.
80**
81** If you wish to acknowledge the SOFA heritage, please acknowledge
82** that you are using a library derived from SOFA, rather than SOFA
83** itself.
84**
85**
86** TERMS AND CONDITIONS
87**
88** Redistribution and use in source and binary forms, with or without
89** modification, are permitted provided that the following conditions
90** are met:
91**
92** 1 Redistributions of source code must retain the above copyright
93** notice, this list of conditions and the following disclaimer.
94**
95** 2 Redistributions in binary form must reproduce the above copyright
96** notice, this list of conditions and the following disclaimer in
97** the documentation and/or other materials provided with the
98** distribution.
99**
100** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
101** the International Astronomical Union nor the names of its
102** contributors may be used to endorse or promote products derived
103** from this software without specific prior written permission.
104**
105** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
106** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
107** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
108** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
109** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
110** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
111** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
112** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
113** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
114** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
115** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
116** POSSIBILITY OF SUCH DAMAGE.
117**
118*/
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