File Coverage

erfasrc/src/ltp.c

Criterion	Covered	Total	%
statement	0	11	0.0
branch	0	2	0.0
condition			n/a
subroutine			n/a
pod			n/a
total	0	13	0.0

line	stmt	bran	code
1			#include "erfa.h"
2
3	0		void eraLtp(double epj, double rp[3][3])
4			/*
5			** - - - - - - -
6			** e r a L t p
7			** - - - - - - -
8			**
9			** Long-term precession matrix.
10			**
11			** Given:
12			** epj double Julian epoch (TT)
13			**
14			** Returned:
15			** rp double[3][3] precession matrix, J2000.0 to date
16			**
17			** Notes:
18			**
19			** 1) The matrix is in the sense
20			**
21			** P_date = rp x P_J2000,
22			**
23			** where P_J2000 is a vector with respect to the J2000.0 mean
24			** equator and equinox and P_date is the same vector with respect to
25			** the equator and equinox of epoch epj.
26			**
27			** 2) The Vondrak et al. (2011, 2012) 400 millennia precession model
28			** agrees with the IAU 2006 precession at J2000.0 and stays within
29			** 100 microarcseconds during the 20th and 21st centuries. It is
30			** accurate to a few arcseconds throughout the historical period,
31			** worsening to a few tenths of a degree at the end of the
32			** +/- 200,000 year time span.
33			**
34			** Called:
35			** eraLtpequ equator pole, long term
36			** eraLtpecl ecliptic pole, long term
37			** eraPxp vector product
38			** eraPn normalize vector
39			**
40			** References:
41			**
42			** Vondrak, J., Capitaine, N. and Wallace, P., 2011, New precession
43			** expressions, valid for long time intervals, Astron.Astrophys. 534,
44			** A22
45			**
46			** Vondrak, J., Capitaine, N. and Wallace, P., 2012, New precession
47			** expressions, valid for long time intervals (Corrigendum),
48			** Astron.Astrophys. 541, C1
49			**
50			** Copyright (C) 2013-2019, NumFOCUS Foundation.
51			** Derived, with permission, from the SOFA library. See notes at end of file.
52			*/
53			{
54			int i;
55			double peqr[3], pecl[3], v[3], w, eqx[3];
56
57
58			/* Equator pole (bottom row of matrix). */
59	0		eraLtpequ(epj, peqr);
60
61			/* Ecliptic pole. */
62	0		eraLtpecl(epj, pecl);
63
64			/* Equinox (top row of matrix). */
65	0		eraPxp(peqr, pecl, v);
66	0		eraPn(v, &w, eqx);
67
68			/* Middle row of matrix. */
69	0		eraPxp(peqr, eqx, v);
70
71			/* Assemble the matrix. */
72	0	0	for ( i = 0; i < 3; i++ ) {
73	0		rp[0][i] = eqx[i];
74	0		rp[1][i] = v[i];
75	0		rp[2][i] = peqr[i];
76			}
77
78	0		}
79			/*----------------------------------------------------------------------
80			**
81			**
82			** Copyright (C) 2013-2019, NumFOCUS Foundation.
83			** All rights reserved.
84			**
85			** This library is derived, with permission, from the International
86			** Astronomical Union's "Standards of Fundamental Astronomy" library,
87			** available from http://www.iausofa.org.
88			**
89			** The ERFA version is intended to retain identical functionality to
90			** the SOFA library, but made distinct through different function and
91			** file names, as set out in the SOFA license conditions. The SOFA
92			** original has a role as a reference standard for the IAU and IERS,
93			** and consequently redistribution is permitted only in its unaltered
94			** state. The ERFA version is not subject to this restriction and
95			** therefore can be included in distributions which do not support the
96			** concept of "read only" software.
97			**
98			** Although the intent is to replicate the SOFA API (other than
99			** replacement of prefix names) and results (with the exception of
100			** bugs; any that are discovered will be fixed), SOFA is not
101			** responsible for any errors found in this version of the library.
102			**
103			** If you wish to acknowledge the SOFA heritage, please acknowledge
104			** that you are using a library derived from SOFA, rather than SOFA
105			** itself.
106			**
107			**
108			** TERMS AND CONDITIONS
109			**
110			** Redistribution and use in source and binary forms, with or without
111			** modification, are permitted provided that the following conditions
112			** are met:
113			**
114			** 1 Redistributions of source code must retain the above copyright
115			** notice, this list of conditions and the following disclaimer.
116			**
117			** 2 Redistributions in binary form must reproduce the above copyright
118			** notice, this list of conditions and the following disclaimer in
119			** the documentation and/or other materials provided with the
120			** distribution.
121			**
122			** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
123			** the International Astronomical Union nor the names of its
124			** contributors may be used to endorse or promote products derived
125			** from this software without specific prior written permission.
126			**
127			** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
128			** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
129			** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
130			** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
131			** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
132			** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
133			** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
134			** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
135			** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
136			** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
137			** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
138			** POSSIBILITY OF SUCH DAMAGE.
139			**
140			*/