FACT++  1.0
fw2m.c
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1 #include "erfa.h"
2 
3 void 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
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140 ** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
141 ** POSSIBILITY OF SUCH DAMAGE.
142 **
143 */
eraRx
void eraRx(double phi, double r[3][3])
Definition: rx.c:3
eraIr
void eraIr(double r[3][3])
Definition: ir.c:3
eraRz
void eraRz(double psi, double r[3][3])
Definition: rz.c:3
eraFw2m
void eraFw2m(double gamb, double phib, double psi, double eps, double r[3][3])
Definition: fw2m.c:3