File Coverage

erfasrc/src/fw2xy.c
Criterion Covered Total %
statement 0 4 0.0
branch n/a
condition n/a
subroutine n/a
pod n/a
total 0 4 0.0


line stmt bran cond sub pod time code
1             #include "erfa.h"
2              
3 0           void eraFw2xy(double gamb, double phib, double psi, double eps,
4             double *x, double *y)
5             /*
6             ** - - - - - - - - -
7             ** e r a F w 2 x y
8             ** - - - - - - - - -
9             **
10             ** CIP X,Y given Fukushima-Williams bias-precession-nutation 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             ** x,y double CIP unit vector X,Y
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(-epsA).R_3(-psi).R_1(phib).R_3(gamb)
41             **
42             ** The returned values x,y are elements [2][0] and [2][1] of the
43             ** matrix. Near J2000.0, they are essentially angles in radians.
44             **
45             ** Called:
46             ** eraFw2m F-W angles to r-matrix
47             ** eraBpn2xy extract CIP X,Y coordinates from NPB matrix
48             **
49             ** Reference:
50             **
51             ** Hilton, J. et al., 2006, Celest.Mech.Dyn.Astron. 94, 351
52             **
53             ** Copyright (C) 2013-2020, NumFOCUS Foundation.
54             ** Derived, with permission, from the SOFA library. See notes at end of file.
55             */
56             {
57             double r[3][3];
58              
59              
60             /* Form NxPxB matrix. */
61 0           eraFw2m(gamb, phib, psi, eps, r);
62              
63             /* Extract CIP X,Y. */
64 0           eraBpn2xy(r, x, y);
65              
66 0           return;
67              
68             }
69             /*----------------------------------------------------------------------
70             **
71             **
72             ** Copyright (C) 2013-2020, NumFOCUS Foundation.
73             ** All rights reserved.
74             **
75             ** This library is derived, with permission, from the International
76             ** Astronomical Union's "Standards of Fundamental Astronomy" library,
77             ** available from http://www.iausofa.org.
78             **
79             ** The ERFA version is intended to retain identical functionality to
80             ** the SOFA library, but made distinct through different function and
81             ** file names, as set out in the SOFA license conditions. The SOFA
82             ** original has a role as a reference standard for the IAU and IERS,
83             ** and consequently redistribution is permitted only in its unaltered
84             ** state. The ERFA version is not subject to this restriction and
85             ** therefore can be included in distributions which do not support the
86             ** concept of "read only" software.
87             **
88             ** Although the intent is to replicate the SOFA API (other than
89             ** replacement of prefix names) and results (with the exception of
90             ** bugs; any that are discovered will be fixed), SOFA is not
91             ** responsible for any errors found in this version of the library.
92             **
93             ** If you wish to acknowledge the SOFA heritage, please acknowledge
94             ** that you are using a library derived from SOFA, rather than SOFA
95             ** itself.
96             **
97             **
98             ** TERMS AND CONDITIONS
99             **
100             ** Redistribution and use in source and binary forms, with or without
101             ** modification, are permitted provided that the following conditions
102             ** are met:
103             **
104             ** 1 Redistributions of source code must retain the above copyright
105             ** notice, this list of conditions and the following disclaimer.
106             **
107             ** 2 Redistributions in binary form must reproduce the above copyright
108             ** notice, this list of conditions and the following disclaimer in
109             ** the documentation and/or other materials provided with the
110             ** distribution.
111             **
112             ** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
113             ** the International Astronomical Union nor the names of its
114             ** contributors may be used to endorse or promote products derived
115             ** from this software without specific prior written permission.
116             **
117             ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
118             ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
119             ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
120             ** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
121             ** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
122             ** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
123             ** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
124             ** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
125             ** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
126             ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
127             ** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
128             ** POSSIBILITY OF SUCH DAMAGE.
129             **
130             */