1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
|
/* ../src/cal2jd.f -- translated by f2c (version 20090411).
You must link the resulting object file with libf2c:
on Microsoft Windows system, link with libf2c.lib;
on Linux or Unix systems, link with .../path/to/libf2c.a -lm
or, if you install libf2c.a in a standard place, with -lf2c -lm
-- in that order, at the end of the command line, as in
cc *.o -lf2c -lm
Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
http://www.netlib.org/f2c/libf2c.zip
*/
#include "f2c.h"
/* Subroutine */ int cal2jd_(integer *iy, integer *im, integer *id,
doublereal *djm0, doublereal *djm, integer *j)
{
/* Initialized data */
static integer mtab[12] = { 31,28,31,30,31,30,31,31,30,31,30,31 };
static integer my, iypmy;
/* + */
/* - - - - - - - - - - - */
/* C A L 2 J D */
/* - - - - - - - - - - - */
/* Gregorian Calendar to Julian Date. */
/* This routine is part of the International Astronomical Union's */
/* SOFA (Standards of Fundamental Astronomy) software collection. */
/* Status: support routine. */
/* Given: */
/* IY,IM,ID i year, month, day in Gregorian calendar (Note 1) */
/* Returned: */
/* DJM0 d MJD zero-point: always 2400000.5 */
/* DJM d Modified Julian Date for 0 hrs */
/* J i status: */
/* 0 = OK */
/* -1 = bad year (Note 3: JD not computed) */
/* -2 = bad month (JD not computed) */
/* -3 = bad day (JD computed) */
/* Notes: */
/* 1) The algorithm used is valid from -4800 March 1, but this */
/* implementation rejects dates before -4799 January 1. */
/* 2) The Julian Date is returned in two pieces, in the usual SOFA */
/* manner, which is designed to preserve time resolution. The */
/* Julian Date is available as a single number by adding DJM0 and */
/* DJM. */
/* 3) In early eras the conversion is from the "Proleptic Gregorian */
/* Calendar"; no account is taken of the date(s) of adoption of */
/* the Gregorian Calendar, nor is the AD/BC numbering convention */
/* observed. */
/* Reference: */
/* Explanatory Supplement to the Astronomical Almanac, */
/* P. Kenneth Seidelmann (ed), University Science Books (1992), */
/* Section 12.92 (p604). */
/* This revision: 2001 September 16 */
/* Copyright (C) 2008 IAU SOFA Review Board. See notes at end. */
/* ----------------------------------------------------------------------- */
/* Earliest year allowed (4800BC) */
/* Month lengths in days */
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
/* Preset status. */
*j = 0;
/* Validate year. */
if (*iy < -4799) {
*j = -1;
} else {
/* Validate month. */
if (*im >= 1 && *im <= 12) {
/* Allow for leap year. */
if (*iy % 4 == 0) {
mtab[1] = 29;
} else {
mtab[1] = 28;
}
if (*iy % 100 == 0 && *iy % 400 != 0) {
mtab[1] = 28;
}
/* Validate day. */
if (*id < 1 || *id > mtab[*im - 1]) {
*j = -3;
}
/* Result. */
my = (*im - 14) / 12;
iypmy = *iy + my;
*djm0 = 2400000.5;
*djm = (doublereal) ((iypmy + 4800) * 1461 / 4 + (*im - 2 - my *
12) * 367 / 12 - (iypmy + 4900) / 100 * 3 / 4 + *id -
2432076);
/* Bad month */
} else {
*j = -2;
}
}
/* Finished. */
/* +----------------------------------------------------------------------- */
/* Copyright (C) 2008 */
/* Standards Of Fundamental Astronomy Review Board */
/* of the International Astronomical Union. */
/* ===================== */
/* SOFA Software License */
/* ===================== */
/* NOTICE TO USER: */
/* BY USING THIS SOFTWARE YOU ACCEPT THE FOLLOWING TERMS AND CONDITIONS */
/* WHICH APPLY TO ITS USE. */
/* 1. The Software is owned by the IAU SOFA Review Board ("the Board"). */
/* 2. Permission is granted to anyone to use the SOFA software for any */
/* purpose, including commercial applications, free of charge and */
/* without payment of royalties, subject to the conditions and */
/* restrictions listed below. */
/* 3. You (the user) may copy and adapt the SOFA software and its */
/* algorithms for your own purposes and you may copy and distribute */
/* a resulting "derived work" to others on a world-wide, royalty-free */
/* basis, provided that the derived work complies with the following */
/* requirements: */
/* a) Your work shall be marked or carry a statement that it (i) uses */
/* routines and computations derived by you from software provided */
/* by SOFA under license to you; and (ii) does not contain */
/* software provided by SOFA or software that has been distributed */
/* by or endorsed by SOFA. */
/* b) The source code of your derived work must contain descriptions */
/* of how the derived work is based upon and/or differs from the */
/* original SOFA software. */
/* c) The name(s) of all routine(s) that you distribute shall differ */
/* from the SOFA names, even when the SOFA content has not been */
/* otherwise changed. */
/* d) The routine-naming prefix "iau" shall not be used. */
/* e) The origin of the SOFA components of your derived work must not */
/* be misrepresented; you must not claim that you wrote the */
/* original software, nor file a patent application for SOFA */
/* software or algorithms embedded in the SOFA software. */
/* f) These requirements must be reproduced intact in any source */
/* distribution and shall apply to anyone to whom you have granted */
/* a further right to modify the source code of your derived work. */
/* 4. In any published work or commercial products which includes */
/* results achieved by using the SOFA software, you shall acknowledge */
/* that the SOFA software was used in obtaining those results. */
/* 5. You shall not cause the SOFA software to be brought into */
/* disrepute, either by misuse, or use for inappropriate tasks, or by */
/* inappropriate modification. */
/* 6. The SOFA software is provided "as is" and the Board makes no */
/* warranty as to its use or performance. The Board does not and */
/* cannot warrant the performance or results which the user may obtain */
/* by using the SOFA software. The Board makes no warranties, express */
/* or implied, as to non-infringement of third party rights, */
/* merchantability, or fitness for any particular purpose. In no */
/* event will the Board be liable to the user for any consequential, */
/* incidental, or special damages, including any lost profits or lost */
/* savings, even if a Board representative has been advised of such */
/* damages, or for any claim by any third party. */
/* 7. The provision of any version of the SOFA software under the terms */
/* and conditions specified herein does not imply that future */
/* versions will also be made available under the same terms and */
/* conditions. */
/* Correspondence concerning SOFA software should be addressed as */
/* follows: */
/* Internet email: sofa@rl.ac.uk */
/* Postal address: IAU SOFA Center */
/* Rutherford Appleton Laboratory */
/* Chilton, Didcot, Oxon OX11 0QX */
/* United Kingdom */
/* ----------------------------------------------------------------------- */
return 0;
} /* cal2jd_ */
|
