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Diffstat (limited to 'ast/pal/palCaldj.c')
-rw-r--r-- | ast/pal/palCaldj.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/ast/pal/palCaldj.c b/ast/pal/palCaldj.c new file mode 100644 index 0000000..03c6b97 --- /dev/null +++ b/ast/pal/palCaldj.c @@ -0,0 +1,99 @@ +/* +*+ +* Name: +* palCaldj + +* Purpose: +* Gregorian Calendar to Modified Julian Date + +* Language: +* Starlink ANSI C + +* Type of Module: +* Library routine + +* Invocation: +* void palCaldj ( int iy, int im, int id, double *djm, int *j ); + +* Arguments: +* iy = int (Given) +* Year in the Gregorian calendar +* im = int (Given) +* Month in the Gergorian calendar +* id = int (Given) +* Day in the Gregorian calendar +* djm = double * (Returned) +* Modified Julian Date (JD-2400000.5) for 0 hrs +* j = status (Returned) +* 0 = OK. See eraCal2jd for other values. + +* Description: +* Modified Julian Date to Gregorian Calendar with special +* behaviour for 2-digit years relating to 1950 to 2049. + +* Authors: +* PTW: Pat Wallace (STFC) +* TIMJ: Tim Jenness (JAC, Hawaii) +* {enter_new_authors_here} + +* History: +* 2012-02-11 (TIMJ): +* Initial version with documentation taken from Fortran SLA +* Adapted with permission from the Fortran SLALIB library. +* {enter_further_changes_here} + +* Notes: +* - Uses eraCal2jd +* - Unlike eraCal2jd this routine treats the years 0-100 as +* referring to the end of the 20th Century and beginning of +* the 21st Century. If this behaviour is not acceptable +* use the SOFA/ERFA routine directly or palCldj. +* Acceptable years are 00-49, interpreted as 2000-2049, +* 50-99, " " 1950-1999, +* all others, interpreted literally. +* - Unlike SLA this routine will work with negative years. + + +* Copyright: +* Copyright (C) 1995 Rutherford Appleton Laboratory +* Copyright (C) 2012 Science and Technology Facilities Council. +* All Rights Reserved. + +* Licence: +* This program is free software: you can redistribute it and/or +* modify it under the terms of the GNU Lesser General Public +* License as published by the Free Software Foundation, either +* version 3 of the License, or (at your option) any later +* version. +* +* This program is distributed in the hope that it will be useful, +* but WITHOUT ANY WARRANTY; without even the implied warranty of +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +* GNU Lesser General Public License for more details. +* +* You should have received a copy of the GNU Lesser General +* License along with this program. If not, see +* <http://www.gnu.org/licenses/>. + +* Bugs: +* {note_any_bugs_here} +*- +*/ + +#include "pal.h" +#include "palmac.h" +#include "pal1sofa.h" + +void palCaldj ( int iy, int im, int id, double *djm, int *j ) { + int adj = 0; /* Year adjustment */ + double djm0; + + if (iy >= 0 && iy <= 49) { + adj = 2000; + } else if (iy >= 50 && iy <= 99) { + adj = 1900; + } + iy += adj; + + *j = eraCal2jd( iy, im, id, &djm0, djm ); +} |