source: trunk/FACT++/sofa/src/numat.c@ 18358

Last change on this file since 18358 was 18346, checked in by tbretz, 11 years ago
File size: 5.9 KB
Line 
1#include "sofa.h"
2
3void iauNumat(double epsa, double dpsi, double deps, double rmatn[3][3])
4/*
5** - - - - - - - - -
6** i a u N u m a t
7** - - - - - - - - -
8**
9** Form the matrix of nutation.
10**
11** This function is part of the International Astronomical Union's
12** SOFA (Standards Of Fundamental Astronomy) software collection.
13**
14** Status: support function.
15**
16** Given:
17** epsa double mean obliquity of date (Note 1)
18** dpsi,deps double nutation (Note 2)
19**
20** Returned:
21** rmatn double[3][3] nutation matrix (Note 3)
22**
23** Notes:
24**
25** 1) The supplied mean obliquity epsa, must be consistent with the
26** precession-nutation models from which dpsi and deps were obtained.
27**
28** 2) The caller is responsible for providing the nutation components;
29** they are in longitude and obliquity, in radians and are with
30** respect to the equinox and ecliptic of date.
31**
32** 3) The matrix operates in the sense V(true) = rmatn * V(mean),
33** where the p-vector V(true) is with respect to the true
34** equatorial triad of date and the p-vector V(mean) is with
35** respect to the mean equatorial triad of date.
36**
37** Called:
38** iauIr initialize r-matrix to identity
39** iauRx rotate around X-axis
40** iauRz rotate around Z-axis
41**
42** Reference:
43**
44** Explanatory Supplement to the Astronomical Almanac,
45** P. Kenneth Seidelmann (ed), University Science Books (1992),
46** Section 3.222-3 (p114).
47**
48** This revision: 2013 June 18
49**
50** SOFA release 2015-02-09
51**
52** Copyright (C) 2015 IAU SOFA Board. See notes at end.
53*/
54{
55/* Build the rotation matrix. */
56 iauIr(rmatn);
57 iauRx(epsa, rmatn);
58 iauRz(-dpsi, rmatn);
59 iauRx(-(epsa + deps), rmatn);
60
61 return;
62
63/*----------------------------------------------------------------------
64**
65** Copyright (C) 2015
66** Standards Of Fundamental Astronomy Board
67** of the International Astronomical Union.
68**
69** =====================
70** SOFA Software License
71** =====================
72**
73** NOTICE TO USER:
74**
75** BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING SIX TERMS AND
76** CONDITIONS WHICH APPLY TO ITS USE.
77**
78** 1. The Software is owned by the IAU SOFA Board ("SOFA").
79**
80** 2. Permission is granted to anyone to use the SOFA software for any
81** purpose, including commercial applications, free of charge and
82** without payment of royalties, subject to the conditions and
83** restrictions listed below.
84**
85** 3. You (the user) may copy and distribute SOFA source code to others,
86** and use and adapt its code and algorithms in your own software,
87** on a world-wide, royalty-free basis. That portion of your
88** distribution that does not consist of intact and unchanged copies
89** of SOFA source code files is a "derived work" that must comply
90** with the following requirements:
91**
92** a) Your work shall be marked or carry a statement that it
93** (i) uses routines and computations derived by you from
94** software provided by SOFA under license to you; and
95** (ii) does not itself constitute software provided by and/or
96** endorsed by SOFA.
97**
98** b) The source code of your derived work must contain descriptions
99** of how the derived work is based upon, contains and/or differs
100** from the original SOFA software.
101**
102** c) The names of all routines in your derived work shall not
103** include the prefix "iau" or "sofa" or trivial modifications
104** thereof such as changes of case.
105**
106** d) The origin of the SOFA components of your derived work must
107** not be misrepresented; you must not claim that you wrote the
108** original software, nor file a patent application for SOFA
109** software or algorithms embedded in the SOFA software.
110**
111** e) These requirements must be reproduced intact in any source
112** distribution and shall apply to anyone to whom you have
113** granted a further right to modify the source code of your
114** derived work.
115**
116** Note that, as originally distributed, the SOFA software is
117** intended to be a definitive implementation of the IAU standards,
118** and consequently third-party modifications are discouraged. All
119** variations, no matter how minor, must be explicitly marked as
120** such, as explained above.
121**
122** 4. You shall not cause the SOFA software to be brought into
123** disrepute, either by misuse, or use for inappropriate tasks, or
124** by inappropriate modification.
125**
126** 5. The SOFA software is provided "as is" and SOFA makes no warranty
127** as to its use or performance. SOFA does not and cannot warrant
128** the performance or results which the user may obtain by using the
129** SOFA software. SOFA makes no warranties, express or implied, as
130** to non-infringement of third party rights, merchantability, or
131** fitness for any particular purpose. In no event will SOFA be
132** liable to the user for any consequential, incidental, or special
133** damages, including any lost profits or lost savings, even if a
134** SOFA representative has been advised of such damages, or for any
135** claim by any third party.
136**
137** 6. The provision of any version of the SOFA software under the terms
138** and conditions specified herein does not imply that future
139** versions will also be made available under the same terms and
140** conditions.
141*
142** In any published work or commercial product which uses the SOFA
143** software directly, acknowledgement (see www.iausofa.org) is
144** appreciated.
145**
146** Correspondence concerning SOFA software should be addressed as
147** follows:
148**
149** By email: sofa@ukho.gov.uk
150** By post: IAU SOFA Center
151** HM Nautical Almanac Office
152** UK Hydrographic Office
153** Admiralty Way, Taunton
154** Somerset, TA1 2DN
155** United Kingdom
156**
157**--------------------------------------------------------------------*/
158}
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