File Coverage

erfasrc/src/c2ixys.c

Criterion	Covered	Total	%
statement	0	9	0.0
branch	0	2	0.0
condition			n/a
subroutine			n/a
pod			n/a
total	0	11	0.0

line	stmt	bran	code
1			#include "erfa.h"
2
3	0		void eraC2ixys(double x, double y, double s, double rc2i[3][3])
4			/*
5			** - - - - - - - - - -
6			** e r a C 2 i x y s
7			** - - - - - - - - - -
8			**
9			** Form the celestial to intermediate-frame-of-date matrix given the CIP
10			** X,Y and the CIO locator s.
11			**
12			** Given:
13			** x,y double Celestial Intermediate Pole (Note 1)
14			** s double the CIO locator s (Note 2)
15			**
16			** Returned:
17			** rc2i double[3][3] celestial-to-intermediate matrix (Note 3)
18			**
19			** Notes:
20			**
21			** 1) The Celestial Intermediate Pole coordinates are the x,y
22			** components of the unit vector in the Geocentric Celestial
23			** Reference System.
24			**
25			** 2) The CIO locator s (in radians) positions the Celestial
26			** Intermediate Origin on the equator of the CIP.
27			**
28			** 3) The matrix rc2i is the first stage in the transformation from
29			** celestial to terrestrial coordinates:
30			**
31			** [TRS] = RPOM * R_3(ERA) * rc2i * [CRS]
32			**
33			** = RC2T * [CRS]
34			**
35			** where [CRS] is a vector in the Geocentric Celestial Reference
36			** System and [TRS] is a vector in the International Terrestrial
37			** Reference System (see IERS Conventions 2003), ERA is the Earth
38			** Rotation Angle and RPOM is the polar motion matrix.
39			**
40			** Called:
41			** eraIr initialize r-matrix to identity
42			** eraRz rotate around Z-axis
43			** eraRy rotate around Y-axis
44			**
45			** Reference:
46			**
47			** McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003),
48			** IERS Technical Note No. 32, BKG (2004)
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			double r2, e, d;
55
56
57			/* Obtain the spherical angles E and d. */
58	0		r2 = xx + yy;
59	0	0	e = (r2 > 0.0) ? atan2(y, x) : 0.0;
60	0		d = atan(sqrt(r2 / (1.0 - r2)));
61
62			/* Form the matrix. */
63	0		eraIr(rc2i);
64	0		eraRz(e, rc2i);
65	0		eraRy(d, rc2i);
66	0		eraRz(-(e+s), rc2i);
67
68	0		return;
69
70			}
71			/*----------------------------------------------------------------------
72			**
73			**
74			** Copyright (C) 2013-2019, NumFOCUS Foundation.
75			** All rights reserved.
76			**
77			** This library is derived, with permission, from the International
78			** Astronomical Union's "Standards of Fundamental Astronomy" library,
79			** available from http://www.iausofa.org.
80			**
81			** The ERFA version is intended to retain identical functionality to
82			** the SOFA library, but made distinct through different function and
83			** file names, as set out in the SOFA license conditions. The SOFA
84			** original has a role as a reference standard for the IAU and IERS,
85			** and consequently redistribution is permitted only in its unaltered
86			** state. The ERFA version is not subject to this restriction and
87			** therefore can be included in distributions which do not support the
88			** concept of "read only" software.
89			**
90			** Although the intent is to replicate the SOFA API (other than
91			** replacement of prefix names) and results (with the exception of
92			** bugs; any that are discovered will be fixed), SOFA is not
93			** responsible for any errors found in this version of the library.
94			**
95			** If you wish to acknowledge the SOFA heritage, please acknowledge
96			** that you are using a library derived from SOFA, rather than SOFA
97			** itself.
98			**
99			**
100			** TERMS AND CONDITIONS
101			**
102			** Redistribution and use in source and binary forms, with or without
103			** modification, are permitted provided that the following conditions
104			** are met:
105			**
106			** 1 Redistributions of source code must retain the above copyright
107			** notice, this list of conditions and the following disclaimer.
108			**
109			** 2 Redistributions in binary form must reproduce the above copyright
110			** notice, this list of conditions and the following disclaimer in
111			** the documentation and/or other materials provided with the
112			** distribution.
113			**
114			** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
115			** the International Astronomical Union nor the names of its
116			** contributors may be used to endorse or promote products derived
117			** from this software without specific prior written permission.
118			**
119			** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
120			** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
121			** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
122			** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
123			** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
124			** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
125			** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
126			** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
127			** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
128			** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
129			** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
130			** POSSIBILITY OF SUCH DAMAGE.
131			**
132			*/