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author | William Joye <wjoye@cfa.harvard.edu> | 2017-12-08 18:59:21 (GMT) |
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committer | William Joye <wjoye@cfa.harvard.edu> | 2017-12-08 18:59:21 (GMT) |
commit | 4432c8d7e1ccb371db03e13cdb5378fceaa5ad04 (patch) | |
tree | 52449d211eba99b24d2e4f6e66193f9511c60b59 /ast/erfa/taiut1.c | |
parent | d8a2dbd825159e4a57ec0c6f4465f62be9e05111 (diff) | |
download | blt-4432c8d7e1ccb371db03e13cdb5378fceaa5ad04.zip blt-4432c8d7e1ccb371db03e13cdb5378fceaa5ad04.tar.gz blt-4432c8d7e1ccb371db03e13cdb5378fceaa5ad04.tar.bz2 |
upgrade AST
Diffstat (limited to 'ast/erfa/taiut1.c')
-rw-r--r-- | ast/erfa/taiut1.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/ast/erfa/taiut1.c b/ast/erfa/taiut1.c new file mode 100644 index 0000000..4a9a485 --- /dev/null +++ b/ast/erfa/taiut1.c @@ -0,0 +1,120 @@ +#include "erfa.h" + +int eraTaiut1(double tai1, double tai2, double dta, + double *ut11, double *ut12) +/* +** - - - - - - - - - - +** e r a T a i u t 1 +** - - - - - - - - - - +** +** Time scale transformation: International Atomic Time, TAI, to +** Universal Time, UT1. +** +** Given: +** tai1,tai2 double TAI as a 2-part Julian Date +** dta double UT1-TAI in seconds +** +** Returned: +** ut11,ut12 double UT1 as a 2-part Julian Date +** +** Returned (function value): +** int status: 0 = OK +** +** Notes: +** +** 1) tai1+tai2 is Julian Date, apportioned in any convenient way +** between the two arguments, for example where tai1 is the Julian +** Day Number and tai2 is the fraction of a day. The returned +** UT11,UT12 follow suit. +** +** 2) The argument dta, i.e. UT1-TAI, is an observed quantity, and is +** available from IERS tabulations. +** +** Reference: +** +** Explanatory Supplement to the Astronomical Almanac, +** P. Kenneth Seidelmann (ed), University Science Books (1992) +** +** Copyright (C) 2013-2016, NumFOCUS Foundation. +** Derived, with permission, from the SOFA library. See notes at end of file. +*/ +{ + double dtad; + + +/* Result, safeguarding precision. */ + dtad = dta / ERFA_DAYSEC; + if ( tai1 > tai2 ) { + *ut11 = tai1; + *ut12 = tai2 + dtad; + } else { + *ut11 = tai1 + dtad; + *ut12 = tai2; + } + +/* Status (always OK). */ + return 0; + +} +/*---------------------------------------------------------------------- +** +** +** Copyright (C) 2013-2016, NumFOCUS Foundation. +** All rights reserved. +** +** This library is derived, with permission, from the International +** Astronomical Union's "Standards of Fundamental Astronomy" library, +** available from http://www.iausofa.org. +** +** The ERFA version is intended to retain identical functionality to +** the SOFA library, but made distinct through different function and +** file names, as set out in the SOFA license conditions. The SOFA +** original has a role as a reference standard for the IAU and IERS, +** and consequently redistribution is permitted only in its unaltered +** state. The ERFA version is not subject to this restriction and +** therefore can be included in distributions which do not support the +** concept of "read only" software. +** +** Although the intent is to replicate the SOFA API (other than +** replacement of prefix names) and results (with the exception of +** bugs; any that are discovered will be fixed), SOFA is not +** responsible for any errors found in this version of the library. +** +** If you wish to acknowledge the SOFA heritage, please acknowledge +** that you are using a library derived from SOFA, rather than SOFA +** itself. +** +** +** TERMS AND CONDITIONS +** +** Redistribution and use in source and binary forms, with or without +** modification, are permitted provided that the following conditions +** are met: +** +** 1 Redistributions of source code must retain the above copyright +** notice, this list of conditions and the following disclaimer. +** +** 2 Redistributions in binary form must reproduce the above copyright +** notice, this list of conditions and the following disclaimer in +** the documentation and/or other materials provided with the +** distribution. +** +** 3 Neither the name of the Standards Of Fundamental Astronomy Board, +** the International Astronomical Union nor the names of its +** contributors may be used to endorse or promote products derived +** from this software without specific prior written permission. +** +** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS +** FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE +** COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, +** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, +** BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +** LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN +** ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +** POSSIBILITY OF SUCH DAMAGE. +** +*/ |