File Coverage

erfasrc/src/tttcg.c
Criterion Covered Total %
statement 0 7 0.0
branch 0 2 0.0
condition n/a
subroutine n/a
pod n/a
total 0 9 0.0


line stmt bran cond sub pod time code
1             #include "erfa.h"
2              
3 0           int eraTttcg(double tt1, double tt2, double *tcg1, double *tcg2)
4             /*
5             ** - - - - - - - - -
6             ** e r a T t t c g
7             ** - - - - - - - - -
8             **
9             ** Time scale transformation: Terrestrial Time, TT, to Geocentric
10             ** Coordinate Time, TCG.
11             **
12             ** Given:
13             ** tt1,tt2 double TT as a 2-part Julian Date
14             **
15             ** Returned:
16             ** tcg1,tcg2 double TCG as a 2-part Julian Date
17             **
18             ** Returned (function value):
19             ** int status: 0 = OK
20             **
21             ** Note:
22             **
23             ** tt1+tt2 is Julian Date, apportioned in any convenient way between
24             ** the two arguments, for example where tt1 is the Julian Day Number
25             ** and tt2 is the fraction of a day. The returned tcg1,tcg2 follow
26             ** suit.
27             **
28             ** References:
29             **
30             ** McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003),
31             ** IERS Technical Note No. 32, BKG (2004)
32             **
33             ** IAU 2000 Resolution B1.9
34             **
35             ** Copyright (C) 2013-2019, NumFOCUS Foundation.
36             ** Derived, with permission, from the SOFA library. See notes at end of file.
37             */
38             {
39              
40             /* 1977 Jan 1 00:00:32.184 TT, as MJD */
41             static const double t77t = ERFA_DJM77 + ERFA_TTMTAI/ERFA_DAYSEC;
42              
43             /* TT to TCG rate */
44             static const double elgg = ERFA_ELG/(1.0-ERFA_ELG);
45              
46              
47             /* Result, safeguarding precision. */
48 0 0         if ( tt1 > tt2 ) {
49 0           *tcg1 = tt1;
50 0           *tcg2 = tt2 + ( ( tt1 - ERFA_DJM0 ) + ( tt2 - t77t ) ) * elgg;
51             } else {
52 0           *tcg1 = tt1 + ( ( tt2 - ERFA_DJM0 ) + ( tt1 - t77t ) ) * elgg;
53 0           *tcg2 = tt2;
54             }
55              
56             /* Status (always OK). */
57 0           return 0;
58              
59             }
60             /*----------------------------------------------------------------------
61             **
62             **
63             ** Copyright (C) 2013-2019, NumFOCUS Foundation.
64             ** All rights reserved.
65             **
66             ** This library is derived, with permission, from the International
67             ** Astronomical Union's "Standards of Fundamental Astronomy" library,
68             ** available from http://www.iausofa.org.
69             **
70             ** The ERFA version is intended to retain identical functionality to
71             ** the SOFA library, but made distinct through different function and
72             ** file names, as set out in the SOFA license conditions. The SOFA
73             ** original has a role as a reference standard for the IAU and IERS,
74             ** and consequently redistribution is permitted only in its unaltered
75             ** state. The ERFA version is not subject to this restriction and
76             ** therefore can be included in distributions which do not support the
77             ** concept of "read only" software.
78             **
79             ** Although the intent is to replicate the SOFA API (other than
80             ** replacement of prefix names) and results (with the exception of
81             ** bugs; any that are discovered will be fixed), SOFA is not
82             ** responsible for any errors found in this version of the library.
83             **
84             ** If you wish to acknowledge the SOFA heritage, please acknowledge
85             ** that you are using a library derived from SOFA, rather than SOFA
86             ** itself.
87             **
88             **
89             ** TERMS AND CONDITIONS
90             **
91             ** Redistribution and use in source and binary forms, with or without
92             ** modification, are permitted provided that the following conditions
93             ** are met:
94             **
95             ** 1 Redistributions of source code must retain the above copyright
96             ** notice, this list of conditions and the following disclaimer.
97             **
98             ** 2 Redistributions in binary form must reproduce the above copyright
99             ** notice, this list of conditions and the following disclaimer in
100             ** the documentation and/or other materials provided with the
101             ** distribution.
102             **
103             ** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
104             ** the International Astronomical Union nor the names of its
105             ** contributors may be used to endorse or promote products derived
106             ** from this software without specific prior written permission.
107             **
108             ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
109             ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
110             ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
111             ** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
112             ** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
113             ** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
114             ** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
115             ** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
116             ** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
117             ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
118             ** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
119             ** POSSIBILITY OF SUCH DAMAGE.
120             **
121             */