File Coverage

erfasrc/src/c2ixy.c

Criterion	Covered	Total	%
statement	0	3	0.0
branch			n/a
condition			n/a
subroutine			n/a
pod			n/a
total	0	3	0.0

line	stmt	code
1		#include "erfa.h"
2
3	0	void eraC2ixy(double date1, double date2, double x, double y,
4		double rc2i[3][3])
5		/*
6		** - - - - - - - - -
7		** e r a C 2 i x y
8		** - - - - - - - - -
9		**
10		** Form the celestial to intermediate-frame-of-date matrix for a given
11		** date when the CIP X,Y coordinates are known. IAU 2000.
12		**
13		** Given:
14		** date1,date2 double TT as a 2-part Julian Date (Note 1)
15		** x,y double Celestial Intermediate Pole (Note 2)
16		**
17		** Returned:
18		** rc2i double[3][3] celestial-to-intermediate matrix (Note 3)
19		**
20		** Notes:
21		**
22		** 1) The TT date date1+date2 is a Julian Date, apportioned in any
23		** convenient way between the two arguments. For example,
24		** JD(TT)=2450123.7 could be expressed in any of these ways,
25		** among others:
26		**
27		** date1 date2
28		**
29		** 2450123.7 0.0 (JD method)
30		** 2451545.0 -1421.3 (J2000 method)
31		** 2400000.5 50123.2 (MJD method)
32		** 2450123.5 0.2 (date & time method)
33		**
34		** The JD method is the most natural and convenient to use in
35		** cases where the loss of several decimal digits of resolution
36		** is acceptable. The J2000 method is best matched to the way
37		** the argument is handled internally and will deliver the
38		** optimum resolution. The MJD method and the date & time methods
39		** are both good compromises between resolution and convenience.
40		**
41		** 2) The Celestial Intermediate Pole coordinates are the x,y components
42		** of the unit vector in the Geocentric Celestial Reference System.
43		**
44		** 3) The matrix rc2i is the first stage in the transformation from
45		** celestial to terrestrial coordinates:
46		**
47		** [TRS] = RPOM * R_3(ERA) * rc2i * [CRS]
48		**
49		** = RC2T * [CRS]
50		**
51		** where [CRS] is a vector in the Geocentric Celestial Reference
52		** System and [TRS] is a vector in the International Terrestrial
53		** Reference System (see IERS Conventions 2003), ERA is the Earth
54		** Rotation Angle and RPOM is the polar motion matrix.
55		**
56		** 4) Although its name does not include "00", This function is in fact
57		** specific to the IAU 2000 models.
58		**
59		** Called:
60		** eraC2ixys celestial-to-intermediate matrix, given X,Y and s
61		** eraS00 the CIO locator s, given X,Y, IAU 2000A
62		**
63		** Reference:
64		**
65		** McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003),
66		** IERS Technical Note No. 32, BKG (2004)
67		**
68		** Copyright (C) 2013-2020, NumFOCUS Foundation.
69		** Derived, with permission, from the SOFA library. See notes at end of file.
70		*/
71
72		{
73		/* Compute s and then the matrix. */
74	0	eraC2ixys(x, y, eraS00(date1, date2, x, y), rc2i);
75
76	0	return;
77
78		}
79		/*----------------------------------------------------------------------
80		**
81		**
82		** Copyright (C) 2013-2020, 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		*/