File Coverage

erfasrc/src/fw2m.c

Criterion	Covered	Total	%
statement	7	7	100.0
branch			n/a
condition			n/a
subroutine			n/a
pod			n/a
total	7	7	100.0

line	stmt	code
1		#include "erfa.h"
2
3	197	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) The present function can construct three different matrices,
43		** depending on which angles are supplied as the arguments gamb,
44		** phib, psi and eps:
45		**
46		** o To obtain the nutation x precession x frame bias matrix,
47		** first generate the four precession angles known conventionally
48		** as gamma_bar, phi_bar, psi_bar and epsilon_A, then generate
49		** the nutation components Dpsi and Depsilon and add them to
50		** psi_bar and epsilon_A, and finally call the present function
51		** using those four angles as arguments.
52		**
53		** o To obtain the precession x frame bias matrix, generate the
54		** four precession angles and call the present function.
55		**
56		** o To obtain the frame bias matrix, generate the four precession
57		** angles for date J2000.0 and call the present function.
58		**
59		** The nutation-only and precession-only matrices can if necessary
60		** be obtained by combining these three appropriately.
61		**
62		** Called:
63		** eraIr initialize r-matrix to identity
64		** eraRz rotate around Z-axis
65		** eraRx rotate around X-axis
66		**
67		** References:
68		**
69		** Capitaine, N. & Wallace, P.T., 2006, Astron.Astrophys. 450, 855
70		** Hilton, J. et al., 2006, Celest.Mech.Dyn.Astron. 94, 351
71		**
72		** Copyright (C) 2013-2020, NumFOCUS Foundation.
73		** Derived, with permission, from the SOFA library. See notes at end of file.
74		*/
75		{
76		/* Construct the matrix. */
77	197	eraIr(r);
78	197	eraRz(gamb, r);
79	197	eraRx(phib, r);
80	197	eraRz(-psi, r);
81	197	eraRx(-eps, r);
82
83	197	return;
84
85		}
86		/*----------------------------------------------------------------------
87		**
88		**
89		** Copyright (C) 2013-2020, NumFOCUS Foundation.
90		** All rights reserved.
91		**
92		** This library is derived, with permission, from the International
93		** Astronomical Union's "Standards of Fundamental Astronomy" library,
94		** available from http://www.iausofa.org.
95		**
96		** The ERFA version is intended to retain identical functionality to
97		** the SOFA library, but made distinct through different function and
98		** file names, as set out in the SOFA license conditions. The SOFA
99		** original has a role as a reference standard for the IAU and IERS,
100		** and consequently redistribution is permitted only in its unaltered
101		** state. The ERFA version is not subject to this restriction and
102		** therefore can be included in distributions which do not support the
103		** concept of "read only" software.
104		**
105		** Although the intent is to replicate the SOFA API (other than
106		** replacement of prefix names) and results (with the exception of
107		** bugs; any that are discovered will be fixed), SOFA is not
108		** responsible for any errors found in this version of the library.
109		**
110		** If you wish to acknowledge the SOFA heritage, please acknowledge
111		** that you are using a library derived from SOFA, rather than SOFA
112		** itself.
113		**
114		**
115		** TERMS AND CONDITIONS
116		**
117		** Redistribution and use in source and binary forms, with or without
118		** modification, are permitted provided that the following conditions
119		** are met:
120		**
121		** 1 Redistributions of source code must retain the above copyright
122		** notice, this list of conditions and the following disclaimer.
123		**
124		** 2 Redistributions in binary form must reproduce the above copyright
125		** notice, this list of conditions and the following disclaimer in
126		** the documentation and/or other materials provided with the
127		** distribution.
128		**
129		** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
130		** the International Astronomical Union nor the names of its
131		** contributors may be used to endorse or promote products derived
132		** from this software without specific prior written permission.
133		**
134		** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
135		** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
136		** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
137		** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
138		** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
139		** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
140		** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
141		** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
142		** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
143		** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
144		** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
145		** POSSIBILITY OF SUCH DAMAGE.
146		**
147		*/