source: trunk/FACT++/pal/palDjcal.c

Last change on this file was 18347, checked in by tbretz, 9 years ago
File size: 2.5 KB
Line 
1/*
2*+
3* Name:
4* palDjcal
5
6* Purpose:
7* Modified Julian Date to Gregorian Calendar
8
9* Language:
10* Starlink ANSI C
11
12* Type of Module:
13* Library routine
14
15* Invocation:
16* void palDjcal ( int ndp, double djm, int iymdf[4], int *j );
17
18* Arguments:
19* ndp = int (Given)
20* Number of decimal places of days in fraction.
21* djm = double (Given)
22* Modified Julian Date (JD-2400000.5)
23* iymdf[4] = int[] (Returned)
24* Year, month, day, fraction in Gregorian calendar.
25* j = status (Returned)
26* 0 = OK. See eraJd2cal for other values.
27
28* Description:
29* Modified Julian Date to Gregorian Calendar, expressed
30* in a form convenient for formatting messages (namely
31* rounded to a specified precision, and with the fields
32* stored in a single array)
33
34* Authors:
35* PTW: Pat Wallace (STFC)
36* TIMJ: Tim Jenness (JAC, Hawaii)
37* {enter_new_authors_here}
38
39* History:
40* 2012-02-10 (TIMJ):
41* Initial version with documentation taken from Fortran SLA
42* Adapted with permission from the Fortran SLALIB library.
43* {enter_further_changes_here}
44
45* Notes:
46* - Uses eraJd2cal
47
48* Copyright:
49* Copyright (C) 2004 Patrick T. Wallace
50* Copyright (C) 2012 Science and Technology Facilities Council.
51* All Rights Reserved.
52
53* Licence:
54* This program is free software: you can redistribute it and/or
55* modify it under the terms of the GNU Lesser General Public
56* License as published by the Free Software Foundation, either
57* version 3 of the License, or (at your option) any later
58* version.
59*
60* This program is distributed in the hope that it will be useful,
61* but WITHOUT ANY WARRANTY; without even the implied warranty of
62* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
63* GNU Lesser General Public License for more details.
64*
65* You should have received a copy of the GNU Lesser General
66* License along with this program. If not, see
67* <http://www.gnu.org/licenses/>.
68
69* Bugs:
70* {note_any_bugs_here}
71*-
72*/
73
74#include <math.h>
75
76#include "pal.h"
77#include "palmac.h"
78#include "pal1sofa.h"
79
80void palDjcal ( int ndp, double djm, int iymdf[4], int *j ) {
81 double frac = 0.0;
82 double nfd;
83
84 *j = eraJd2cal( PAL__MJD0, djm, &(iymdf[0]),
85 &(iymdf[1]), &(iymdf[2]),
86 &frac);
87
88 /* Convert ndp to a power of 10 */
89 nfd = pow( 10., (double)ndp );
90
91 /* Multiply the fraction */
92 frac *= nfd;
93
94 /* and now we want to round to the nearest integer */
95 iymdf[3] = (int)DNINT(frac);
96
97}
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