File Coverage

erfasrc/src/c2i06a.c

Criterion	Covered	Total	%
statement	0	6	0.0
branch			n/a
condition			n/a
subroutine			n/a
pod			n/a
total	0	6	0.0

line	stmt	code
1		#include "erfa.h"
2
3	0	void eraC2i06a(double date1, double date2, double rc2i[3][3])
4		/*
5		** - - - - - - - - - -
6		** e r a C 2 i 0 6 a
7		** - - - - - - - - - -
8		**
9		** Form the celestial-to-intermediate matrix for a given date using the
10		** IAU 2006 precession and IAU 2000A nutation models.
11		**
12		** Given:
13		** date1,date2 double TT as a 2-part Julian Date (Note 1)
14		**
15		** Returned:
16		** rc2i double[3][3] celestial-to-intermediate matrix (Note 2)
17		**
18		** Notes:
19		**
20		** 1) The TT date date1+date2 is a Julian Date, apportioned in any
21		** convenient way between the two arguments. For example,
22		** JD(TT)=2450123.7 could be expressed in any of these ways,
23		** among others:
24		**
25		** date1 date2
26		**
27		** 2450123.7 0.0 (JD method)
28		** 2451545.0 -1421.3 (J2000 method)
29		** 2400000.5 50123.2 (MJD method)
30		** 2450123.5 0.2 (date & time method)
31		**
32		** The JD method is the most natural and convenient to use in
33		** cases where the loss of several decimal digits of resolution
34		** is acceptable. The J2000 method is best matched to the way
35		** the argument is handled internally and will deliver the
36		** optimum resolution. The MJD method and the date & time methods
37		** are both good compromises between resolution and convenience.
38		**
39		** 2) The matrix rc2i is the first stage in the transformation from
40		** celestial to terrestrial coordinates:
41		**
42		** [TRS] = RPOM * R_3(ERA) * rc2i * [CRS]
43		**
44		** = RC2T * [CRS]
45		**
46		** where [CRS] is a vector in the Geocentric Celestial Reference
47		** System and [TRS] is a vector in the International Terrestrial
48		** Reference System (see IERS Conventions 2003), ERA is the Earth
49		** Rotation Angle and RPOM is the polar motion matrix.
50		**
51		** Called:
52		** eraPnm06a classical NPB matrix, IAU 2006/2000A
53		** eraBpn2xy extract CIP X,Y coordinates from NPB matrix
54		** eraS06 the CIO locator s, given X,Y, IAU 2006
55		** eraC2ixys celestial-to-intermediate matrix, given X,Y and s
56		**
57		** References:
58		**
59		** McCarthy, D. D., Petit, G. (eds.), 2004, IERS Conventions (2003),
60		** IERS Technical Note No. 32, BKG
61		**
62		** Copyright (C) 2013-2020, NumFOCUS Foundation.
63		** Derived, with permission, from the SOFA library. See notes at end of file.
64		*/
65		{
66		double rbpn[3][3], x, y, s;
67
68
69		/* Obtain the celestial-to-true matrix (IAU 2006/2000A). */
70	0	eraPnm06a(date1, date2, rbpn);
71
72		/* Extract the X,Y coordinates. */
73	0	eraBpn2xy(rbpn, &x, &y);
74
75		/* Obtain the CIO locator. */
76	0	s = eraS06(date1, date2, x, y);
77
78		/* Form the celestial-to-intermediate matrix. */
79	0	eraC2ixys(x, y, s, rc2i);
80
81	0	return;
82
83		}
84		/*----------------------------------------------------------------------
85		**
86		**
87		** Copyright (C) 2013-2020, NumFOCUS Foundation.
88		** All rights reserved.
89		**
90		** This library is derived, with permission, from the International
91		** Astronomical Union's "Standards of Fundamental Astronomy" library,
92		** available from http://www.iausofa.org.
93		**
94		** The ERFA version is intended to retain identical functionality to
95		** the SOFA library, but made distinct through different function and
96		** file names, as set out in the SOFA license conditions. The SOFA
97		** original has a role as a reference standard for the IAU and IERS,
98		** and consequently redistribution is permitted only in its unaltered
99		** state. The ERFA version is not subject to this restriction and
100		** therefore can be included in distributions which do not support the
101		** concept of "read only" software.
102		**
103		** Although the intent is to replicate the SOFA API (other than
104		** replacement of prefix names) and results (with the exception of
105		** bugs; any that are discovered will be fixed), SOFA is not
106		** responsible for any errors found in this version of the library.
107		**
108		** If you wish to acknowledge the SOFA heritage, please acknowledge
109		** that you are using a library derived from SOFA, rather than SOFA
110		** itself.
111		**
112		**
113		** TERMS AND CONDITIONS
114		**
115		** Redistribution and use in source and binary forms, with or without
116		** modification, are permitted provided that the following conditions
117		** are met:
118		**
119		** 1 Redistributions of source code must retain the above copyright
120		** notice, this list of conditions and the following disclaimer.
121		**
122		** 2 Redistributions in binary form must reproduce the above copyright
123		** notice, this list of conditions and the following disclaimer in
124		** the documentation and/or other materials provided with the
125		** distribution.
126		**
127		** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
128		** the International Astronomical Union nor the names of its
129		** contributors may be used to endorse or promote products derived
130		** from this software without specific prior written permission.
131		**
132		** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
133		** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
134		** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
135		** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
136		** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
137		** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
138		** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
139		** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
140		** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
141		** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
142		** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
143		** POSSIBILITY OF SUCH DAMAGE.
144		**
145		*/