File Coverage

erfasrc/src/ecm06.c

Criterion	Covered	Total	%
statement	0	7	0.0
branch			n/a
condition			n/a
subroutine			n/a
pod			n/a
total	0	7	0.0

line	stmt	code
1		#include "erfa.h"
2
3	0	void eraEcm06(double date1, double date2, double rm[3][3])
4		/*
5		** - - - - - - - - -
6		** e r a E c m 0 6
7		** - - - - - - - - -
8		**
9		** ICRS equatorial to ecliptic rotation matrix, IAU 2006.
10		**
11		** Given:
12		** date1,date2 double TT as a 2-part Julian date (Note 1)
13		**
14		** Returned:
15		** rm double[3][3] ICRS to ecliptic rotation matrix
16		**
17		** Notes:
18		**
19		** 1) The TT date date1+date2 is a Julian Date, apportioned in any
20		** convenient way between the two arguments. For example,
21		** JD(TT)=2450123.7 could be expressed in any of these ways,
22		** among others:
23		**
24		** date1 date2
25		**
26		** 2450123.7 0.0 (JD method)
27		** 2451545.0 -1421.3 (J2000 method)
28		** 2400000.5 50123.2 (MJD method)
29		** 2450123.5 0.2 (date & time method)
30		**
31		** The JD method is the most natural and convenient to use in
32		** cases where the loss of several decimal digits of resolution
33		** is acceptable. The J2000 method is best matched to the way
34		** the argument is handled internally and will deliver the
35		** optimum resolution. The MJD method and the date & time methods
36		** are both good compromises between resolution and convenience.
37		**
38		** 1) The matrix is in the sense
39		**
40		** E_ep = rm x P_ICRS,
41		**
42		** where P_ICRS is a vector with respect to ICRS right ascension
43		** and declination axes and E_ep is the same vector with respect to
44		** the (inertial) ecliptic and equinox of date.
45		**
46		** 2) P_ICRS is a free vector, merely a direction, typically of unit
47		** magnitude, and not bound to any particular spatial origin, such
48		** as the Earth, Sun or SSB. No assumptions are made about whether
49		** it represents starlight and embodies astrometric effects such as
50		** parallax or aberration. The transformation is approximately that
51		** between mean J2000.0 right ascension and declination and ecliptic
52		** longitude and latitude, with only frame bias (always less than
53		** 25 mas) to disturb this classical picture.
54		**
55		** Called:
56		** eraObl06 mean obliquity, IAU 2006
57		** eraPmat06 PB matrix, IAU 2006
58		** eraIr initialize r-matrix to identity
59		** eraRx rotate around X-axis
60		** eraRxr product of two r-matrices
61		**
62		** Copyright (C) 2013-2019, NumFOCUS Foundation.
63		** Derived, with permission, from the SOFA library. See notes at end of file.
64		*/
65		{
66		double ob, bp[3][3], e[3][3];
67
68
69		/* Obliquity, IAU 2006. */
70	0	ob = eraObl06(date1, date2);
71
72		/* Precession-bias matrix, IAU 2006. */
73	0	eraPmat06(date1, date2, bp);
74
75		/* Equatorial of date to ecliptic matrix. */
76	0	eraIr(e);
77	0	eraRx(ob, e);
78
79		/* ICRS to ecliptic coordinates rotation matrix, IAU 2006. */
80	0	eraRxr(e, bp, rm);
81
82	0	}
83		/*----------------------------------------------------------------------
84		**
85		**
86		** Copyright (C) 2013-2019, NumFOCUS Foundation.
87		** All rights reserved.
88		**
89		** This library is derived, with permission, from the International
90		** Astronomical Union's "Standards of Fundamental Astronomy" library,
91		** available from http://www.iausofa.org.
92		**
93		** The ERFA version is intended to retain identical functionality to
94		** the SOFA library, but made distinct through different function and
95		** file names, as set out in the SOFA license conditions. The SOFA
96		** original has a role as a reference standard for the IAU and IERS,
97		** and consequently redistribution is permitted only in its unaltered
98		** state. The ERFA version is not subject to this restriction and
99		** therefore can be included in distributions which do not support the
100		** concept of "read only" software.
101		**
102		** Although the intent is to replicate the SOFA API (other than
103		** replacement of prefix names) and results (with the exception of
104		** bugs; any that are discovered will be fixed), SOFA is not
105		** responsible for any errors found in this version of the library.
106		**
107		** If you wish to acknowledge the SOFA heritage, please acknowledge
108		** that you are using a library derived from SOFA, rather than SOFA
109		** itself.
110		**
111		**
112		** TERMS AND CONDITIONS
113		**
114		** Redistribution and use in source and binary forms, with or without
115		** modification, are permitted provided that the following conditions
116		** are met:
117		**
118		** 1 Redistributions of source code must retain the above copyright
119		** notice, this list of conditions and the following disclaimer.
120		**
121		** 2 Redistributions in binary form must reproduce the above copyright
122		** notice, this list of conditions and the following disclaimer in
123		** the documentation and/or other materials provided with the
124		** distribution.
125		**
126		** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
127		** the International Astronomical Union nor the names of its
128		** contributors may be used to endorse or promote products derived
129		** from this software without specific prior written permission.
130		**
131		** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
132		** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
133		** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
134		** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
135		** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
136		** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
137		** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
138		** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
139		** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
140		** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
141		** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
142		** POSSIBILITY OF SUCH DAMAGE.
143		**
144		*/