source: trunk/FACT++/erfa/src/fw2m.c@ 18350

Last change on this file since 18350 was 18348, checked in by tbretz, 9 years ago
File size: 5.2 KB
Line 
1#include "erfa.h"
2
3void eraFw2m(double gamb, double phib, double psi, double eps,
4 double r[3][3])
5/*
6** - - - - - - - -
7** e r a F w 2 m
8** - - - - - - - -
9**
10** Form rotation matrix given the Fukushima-Williams angles.
11**
12** Given:
13** gamb double F-W angle gamma_bar (radians)
14** phib double F-W angle phi_bar (radians)
15** psi double F-W angle psi (radians)
16** eps double F-W angle epsilon (radians)
17**
18** Returned:
19** r double[3][3] rotation matrix
20**
21** Notes:
22**
23** 1) Naming the following points:
24**
25** e = J2000.0 ecliptic pole,
26** p = GCRS pole,
27** E = ecliptic pole of date,
28** and P = CIP,
29**
30** the four Fukushima-Williams angles are as follows:
31**
32** gamb = gamma = epE
33** phib = phi = pE
34** psi = psi = pEP
35** eps = epsilon = EP
36**
37** 2) The matrix representing the combined effects of frame bias,
38** precession and nutation is:
39**
40** NxPxB = R_1(-eps).R_3(-psi).R_1(phib).R_3(gamb)
41**
42** 3) Three different matrices can be constructed, depending on the
43** supplied angles:
44**
45** o To obtain the nutation x precession x frame bias matrix,
46** generate the four precession angles, generate the nutation
47** components and add them to the psi_bar and epsilon_A angles,
48** and call the present function.
49**
50** o To obtain the precession x frame bias matrix, generate the
51** four precession angles and call the present function.
52**
53** o To obtain the frame bias matrix, generate the four precession
54** angles for date J2000.0 and call the present function.
55**
56** The nutation-only and precession-only matrices can if necessary
57** be obtained by combining these three appropriately.
58**
59** Called:
60** eraIr initialize r-matrix to identity
61** eraRz rotate around Z-axis
62** eraRx rotate around X-axis
63**
64** Reference:
65**
66** Hilton, J. et al., 2006, Celest.Mech.Dyn.Astron. 94, 351
67**
68** Copyright (C) 2013-2015, NumFOCUS Foundation.
69** Derived, with permission, from the SOFA library. See notes at end of file.
70*/
71{
72/* Construct the matrix. */
73 eraIr(r);
74 eraRz(gamb, r);
75 eraRx(phib, r);
76 eraRz(-psi, r);
77 eraRx(-eps, r);
78
79 return;
80
81}
82/*----------------------------------------------------------------------
83**
84**
85** Copyright (C) 2013-2015, NumFOCUS Foundation.
86** All rights reserved.
87**
88** This library is derived, with permission, from the International
89** Astronomical Union's "Standards of Fundamental Astronomy" library,
90** available from http://www.iausofa.org.
91**
92** The ERFA version is intended to retain identical functionality to
93** the SOFA library, but made distinct through different function and
94** file names, as set out in the SOFA license conditions. The SOFA
95** original has a role as a reference standard for the IAU and IERS,
96** and consequently redistribution is permitted only in its unaltered
97** state. The ERFA version is not subject to this restriction and
98** therefore can be included in distributions which do not support the
99** concept of "read only" software.
100**
101** Although the intent is to replicate the SOFA API (other than
102** replacement of prefix names) and results (with the exception of
103** bugs; any that are discovered will be fixed), SOFA is not
104** responsible for any errors found in this version of the library.
105**
106** If you wish to acknowledge the SOFA heritage, please acknowledge
107** that you are using a library derived from SOFA, rather than SOFA
108** itself.
109**
110**
111** TERMS AND CONDITIONS
112**
113** Redistribution and use in source and binary forms, with or without
114** modification, are permitted provided that the following conditions
115** are met:
116**
117** 1 Redistributions of source code must retain the above copyright
118** notice, this list of conditions and the following disclaimer.
119**
120** 2 Redistributions in binary form must reproduce the above copyright
121** notice, this list of conditions and the following disclaimer in
122** the documentation and/or other materials provided with the
123** distribution.
124**
125** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
126** the International Astronomical Union nor the names of its
127** contributors may be used to endorse or promote products derived
128** from this software without specific prior written permission.
129**
130** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
131** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
132** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
133** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
134** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
135** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
136** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
137** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
138** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
139** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
140** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
141** POSSIBILITY OF SUCH DAMAGE.
142**
143*/
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