File Coverage

erfasrc/src/eceq06.c

Criterion	Covered	Total	%
statement	0	8	0.0
branch			n/a
condition			n/a
subroutine			n/a
pod			n/a
total	0	8	0.0

line	stmt	code
1		#include "erfa.h"
2
3	0	void eraEceq06(double date1, double date2, double dl, double db,
4		double dr, double dd)
5		/*
6		** - - - - - - - - - -
7		** e r a E c e q 0 6
8		** - - - - - - - - - -
9		**
10		** Transformation from ecliptic coordinates (mean equinox and ecliptic
11		** of date) to ICRS RA,Dec, using the IAU 2006 precession model.
12		**
13		** Given:
14		** date1,date2 double TT as a 2-part Julian date (Note 1)
15		** dl,db double ecliptic longitude and latitude (radians)
16		**
17		** Returned:
18		** dr,dd double ICRS right ascension and declination (radians)
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) No assumptions are made about whether the coordinates represent
40		** starlight and embody astrometric effects such as parallax or
41		** aberration.
42		**
43		** 3) The transformation is approximately that from ecliptic longitude
44		** and latitude (mean equinox and ecliptic of date) to mean J2000.0
45		** right ascension and declination, with only frame bias (always
46		** less than 25 mas) to disturb this classical picture.
47		**
48		** Called:
49		** eraS2c spherical coordinates to unit vector
50		** eraEcm06 J2000.0 to ecliptic rotation matrix, IAU 2006
51		** eraTrxp product of transpose of r-matrix and p-vector
52		** eraC2s unit vector to spherical coordinates
53		** eraAnp normalize angle into range 0 to 2pi
54		** eraAnpm normalize angle into range +/- pi
55		**
56		** Copyright (C) 2013-2020, NumFOCUS Foundation.
57		** Derived, with permission, from the SOFA library. See notes at end of file.
58		*/
59		{
60		double rm[3][3], v1[3], v2[3], a, b;
61
62
63		/* Spherical to Cartesian. */
64	0	eraS2c(dl, db, v1);
65
66		/* Rotation matrix, ICRS equatorial to ecliptic. */
67	0	eraEcm06(date1, date2, rm);
68
69		/* The transformation from ecliptic to ICRS. */
70	0	eraTrxp(rm, v1, v2);
71
72		/* Cartesian to spherical. */
73	0	eraC2s(v2, &a, &b);
74
75		/* Express in conventional ranges. */
76	0	*dr = eraAnp(a);
77	0	*dd = eraAnpm(b);
78
79	0	}
80		/*----------------------------------------------------------------------
81		**
82		**
83		** Copyright (C) 2013-2020, NumFOCUS Foundation.
84		** All rights reserved.
85		**
86		** This library is derived, with permission, from the International
87		** Astronomical Union's "Standards of Fundamental Astronomy" library,
88		** available from http://www.iausofa.org.
89		**
90		** The ERFA version is intended to retain identical functionality to
91		** the SOFA library, but made distinct through different function and
92		** file names, as set out in the SOFA license conditions. The SOFA
93		** original has a role as a reference standard for the IAU and IERS,
94		** and consequently redistribution is permitted only in its unaltered
95		** state. The ERFA version is not subject to this restriction and
96		** therefore can be included in distributions which do not support the
97		** concept of "read only" software.
98		**
99		** Although the intent is to replicate the SOFA API (other than
100		** replacement of prefix names) and results (with the exception of
101		** bugs; any that are discovered will be fixed), SOFA is not
102		** responsible for any errors found in this version of the library.
103		**
104		** If you wish to acknowledge the SOFA heritage, please acknowledge
105		** that you are using a library derived from SOFA, rather than SOFA
106		** itself.
107		**
108		**
109		** TERMS AND CONDITIONS
110		**
111		** Redistribution and use in source and binary forms, with or without
112		** modification, are permitted provided that the following conditions
113		** are met:
114		**
115		** 1 Redistributions of source code must retain the above copyright
116		** notice, this list of conditions and the following disclaimer.
117		**
118		** 2 Redistributions in binary form must reproduce the above copyright
119		** notice, this list of conditions and the following disclaimer in
120		** the documentation and/or other materials provided with the
121		** distribution.
122		**
123		** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
124		** the International Astronomical Union nor the names of its
125		** contributors may be used to endorse or promote products derived
126		** from this software without specific prior written permission.
127		**
128		** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
129		** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
130		** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
131		** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
132		** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
133		** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
134		** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
135		** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
136		** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
137		** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
138		** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
139		** POSSIBILITY OF SUCH DAMAGE.
140		**
141		*/