File Coverage

erfasrc/src/utcut1.c
Criterion Covered Total %
statement 0 10 0.0
branch 0 10 0.0
condition n/a
subroutine n/a
pod n/a
total 0 20 0.0


line stmt bran cond sub pod time code
1             #include "erfa.h"
2              
3 0           int eraUtcut1(double utc1, double utc2, double dut1,
4             double *ut11, double *ut12)
5             /*
6             ** - - - - - - - - - -
7             ** e r a U t c u t 1
8             ** - - - - - - - - - -
9             **
10             ** Time scale transformation: Coordinated Universal Time, UTC, to
11             ** Universal Time, UT1.
12             **
13             ** Given:
14             ** utc1,utc2 double UTC as a 2-part quasi Julian Date (Notes 1-4)
15             ** dut1 double Delta UT1 = UT1-UTC in seconds (Note 5)
16             **
17             ** Returned:
18             ** ut11,ut12 double UT1 as a 2-part Julian Date (Note 6)
19             **
20             ** Returned (function value):
21             ** int status: +1 = dubious year (Note 3)
22             ** 0 = OK
23             ** -1 = unacceptable date
24             **
25             ** Notes:
26             **
27             ** 1) utc1+utc2 is quasi Julian Date (see Note 2), apportioned in any
28             ** convenient way between the two arguments, for example where utc1
29             ** is the Julian Day Number and utc2 is the fraction of a day.
30             **
31             ** 2) JD cannot unambiguously represent UTC during a leap second unless
32             ** special measures are taken. The convention in the present
33             ** function is that the JD day represents UTC days whether the
34             ** length is 86399, 86400 or 86401 SI seconds.
35             **
36             ** 3) The warning status "dubious year" flags UTCs that predate the
37             ** introduction of the time scale or that are too far in the future
38             ** to be trusted. See eraDat for further details.
39             **
40             ** 4) The function eraDtf2d converts from calendar date and time of
41             ** day into 2-part Julian Date, and in the case of UTC implements
42             ** the leap-second-ambiguity convention described above.
43             **
44             ** 5) Delta UT1 can be obtained from tabulations provided by the
45             ** International Earth Rotation and Reference Systems Service.
46             ** It is the caller's responsibility to supply a dut1 argument
47             ** containing the UT1-UTC value that matches the given UTC.
48             **
49             ** 6) The returned ut11,ut12 are such that their sum is the UT1 Julian
50             ** Date.
51             **
52             ** References:
53             **
54             ** McCarthy, D. D., Petit, G. (eds.), IERS Conventions (2003),
55             ** IERS Technical Note No. 32, BKG (2004)
56             **
57             ** Explanatory Supplement to the Astronomical Almanac,
58             ** P. Kenneth Seidelmann (ed), University Science Books (1992)
59             **
60             ** Called:
61             ** eraJd2cal JD to Gregorian calendar
62             ** eraDat delta(AT) = TAI-UTC
63             ** eraUtctai UTC to TAI
64             ** eraTaiut1 TAI to UT1
65             **
66             ** Copyright (C) 2013-2020, NumFOCUS Foundation.
67             ** Derived, with permission, from the SOFA library. See notes at end of file.
68             */
69             {
70             int iy, im, id, js, jw;
71             double w, dat, dta, tai1, tai2;
72              
73              
74             /* Look up TAI-UTC. */
75 0 0         if ( eraJd2cal(utc1, utc2, &iy, &im, &id, &w) ) return -1;
76 0           js = eraDat ( iy, im, id, 0.0, &dat);
77 0 0         if ( js < 0 ) return -1;
78              
79             /* Form UT1-TAI. */
80 0           dta = dut1 - dat;
81              
82             /* UTC to TAI to UT1. */
83 0           jw = eraUtctai(utc1, utc2, &tai1, &tai2);
84 0 0         if ( jw < 0 ) {
85             return -1;
86 0 0         } else if ( jw > 0 ) {
87             js = jw;
88             }
89 0 0         if ( eraTaiut1(tai1, tai2, dta, ut11, ut12) ) return -1;
90              
91             /* Status. */
92 0           return js;
93              
94             }
95             /*----------------------------------------------------------------------
96             **
97             **
98             ** Copyright (C) 2013-2020, NumFOCUS Foundation.
99             ** All rights reserved.
100             **
101             ** This library is derived, with permission, from the International
102             ** Astronomical Union's "Standards of Fundamental Astronomy" library,
103             ** available from http://www.iausofa.org.
104             **
105             ** The ERFA version is intended to retain identical functionality to
106             ** the SOFA library, but made distinct through different function and
107             ** file names, as set out in the SOFA license conditions. The SOFA
108             ** original has a role as a reference standard for the IAU and IERS,
109             ** and consequently redistribution is permitted only in its unaltered
110             ** state. The ERFA version is not subject to this restriction and
111             ** therefore can be included in distributions which do not support the
112             ** concept of "read only" software.
113             **
114             ** Although the intent is to replicate the SOFA API (other than
115             ** replacement of prefix names) and results (with the exception of
116             ** bugs; any that are discovered will be fixed), SOFA is not
117             ** responsible for any errors found in this version of the library.
118             **
119             ** If you wish to acknowledge the SOFA heritage, please acknowledge
120             ** that you are using a library derived from SOFA, rather than SOFA
121             ** itself.
122             **
123             **
124             ** TERMS AND CONDITIONS
125             **
126             ** Redistribution and use in source and binary forms, with or without
127             ** modification, are permitted provided that the following conditions
128             ** are met:
129             **
130             ** 1 Redistributions of source code must retain the above copyright
131             ** notice, this list of conditions and the following disclaimer.
132             **
133             ** 2 Redistributions in binary form must reproduce the above copyright
134             ** notice, this list of conditions and the following disclaimer in
135             ** the documentation and/or other materials provided with the
136             ** distribution.
137             **
138             ** 3 Neither the name of the Standards Of Fundamental Astronomy Board,
139             ** the International Astronomical Union nor the names of its
140             ** contributors may be used to endorse or promote products derived
141             ** from this software without specific prior written permission.
142             **
143             ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
144             ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
145             ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
146             ** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
147             ** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
148             ** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
149             ** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
150             ** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
151             ** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
152             ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
153             ** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
154             ** POSSIBILITY OF SUCH DAMAGE.
155             **
156             */