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/* ../src/dat.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 dat_(integer *iy, integer *im, integer *id, doublereal *
fd, doublereal *deltat, integer *j)
{
/* Initialized data */
static integer idate[78] /* was [2][39] */ = { 1960,1,1961,1,1961,8,
1962,1,1963,11,1964,1,1964,4,1964,9,1965,1,1965,3,1965,7,1965,9,
1966,1,1968,2,1972,1,1972,7,1973,1,1974,1,1975,1,1976,1,1977,1,
1978,1,1979,1,1980,1,1981,7,1982,7,1983,7,1985,7,1988,1,1990,1,
1991,1,1992,7,1993,7,1994,7,1996,1,1997,7,1999,1,2006,1,2009,1 };
static doublereal dats[39] = { 1.417818,1.422818,1.372818,1.845858,
1.945858,3.24013,3.34013,3.44013,3.54013,3.64013,3.74013,3.84013,
4.31317,4.21317,10.,11.,12.,13.,14.,15.,16.,17.,18.,19.,20.,21.,
22.,23.,24.,25.,26.,27.,28.,29.,30.,31.,32.,33.,34. };
static doublereal drift[28] /* was [2][14] */ = { 37300.,.001296,37300.,
.001296,37300.,.001296,37665.,.0011232,37665.,.0011232,38761.,
.001296,38761.,.001296,38761.,.001296,38761.,.001296,38761.,
.001296,38761.,.001296,38761.,.001296,39126.,.002592,39126.,
.002592 };
static integer i__, m;
static doublereal da;
static integer is, js;
static doublereal djm, djm0;
static logical more;
extern /* Subroutine */ int cal2jd_(integer *, integer *, integer *,
doublereal *, doublereal *, integer *);
/* + */
/* - - - - - - - - */
/* D A T */
/* - - - - - - - - */
/* For a given UTC date, calculate delta(AT) = TAI-UTC. */
/* :------------------------------------------: */
/* : : */
/* : IMPORTANT : */
/* : : */
/* : A new version of this routine must be : */
/* : produced whenever a new leap second is : */
/* : announced. There are five items to : */
/* : change on each such occasion: : */
/* : : */
/* : 1) The parameter NDAT must be : */
/* : increased by 1. : */
/* : : */
/* : 2) A new line must be added to the set : */
/* : of DATA statements that initialize : */
/* : the arrays IDATE and DATS. : */
/* : : */
/* : 3) The parameter IYV must be set to : */
/* : the current year. : */
/* : : */
/* : 4) The "Latest leap second" comment : */
/* : below must be set to the new leap : */
/* : second date. : */
/* : : */
/* : 5) The "This revision" comment, later, : */
/* : must be set to the current date. : */
/* : : */
/* : Change (3) must also be carried out : */
/* : whenever the routine is re-issued, : */
/* : even if no leap seconds have been : */
/* : added. : */
/* : : */
/* : Latest leap second: 2008 December 31 : */
/* : : */
/* :__________________________________________: */
/* This routine is part of the International Astronomical Union's */
/* SOFA (Standards of Fundamental Astronomy) software collection. */
/* Status: support routine. */
/* Given: */
/* IY i UTC: year (Notes 1 and 2) */
/* IM i month (Note 2) */
/* ID i day (Notes 2 and 3) */
/* FD d fraction of day (Note 4) */
/* Returned: */
/* DELTAT d TAI minus UTC, seconds */
/* J i status (Note 5): */
/* 1 = dubious year (Note 1) */
/* 0 = OK */
/* -1 = bad year */
/* -2 = bad month */
/* -3 = bad day (Note 3) */
/* -4 = bad fraction (Note 4) */
/* Notes: */
/* 1) UTC began at 1960 January 1.0 (JD 2436934.5) and it is improper */
/* to call the routine with an earlier date. If this is attempted, */
/* zero is returned together with a warning status. */
/* Because leap seconds cannot, in principle, be predicted in */
/* advance, a reliable check for dates beyond the valid range is */
/* impossible. To guard against gross errors, a year five or more */
/* after the release year of the present routine (see parameter IYV) */
/* is considered dubious. In this case a warning status is returned */
/* but the result is computed in the normal way. */
/* For both too-early and too-late years, the warning status is J=+1. */
/* This is distinct from the error status J=-1, which signifies a */
/* year so early that JD could not be computed. */
/* 2) If the specified date is for a day which ends with a leap second, */
/* the UTC-TAI value returned is for the period leading up to the */
/* leap second. If the date is for a day which begins as a leap */
/* second ends, the UTC-TAI returned is for the period following the */
/* leap second. */
/* 3) The day number must be in the normal calendar range, for example */
/* 1 through 30 for April. The "almanac" convention of allowing */
/* such dates as January 0 and December 32 is not supported in this */
/* routine, in order to avoid confusion near leap seconds. */
/* 4) The fraction of day is used only for dates before the introduction */
/* of leap seconds, the first of which occurred at the end of 1971. */
/* It is tested for validity (zero to less than 1 is the valid range) */
/* even if not used; if invalid, zero is used and status J=-4 is */
/* returned. For many applications, setting FD to zero is */
/* acceptable; the resulting error is always less than 3 ms (and */
/* occurs only pre-1972). */
/* 5) The status value returned in the case where there are multiple */
/* errors refers to the first error detected. For example, if the */
/* month and day are 13 and 32 respectively, J=-2 (bad month) will be */
/* returned. */
/* 6) In cases where a valid result is not available, zero is returned. */
/* References: */
/* 1) For dates from 1961 January 1 onwards, the expressions from the */
/* file ftp://maia.usno.navy.mil/ser7/tai-utc.dat are used. */
/* 2) The 5ms timestep at 1961 January 1 is taken from 2.58.1 (p87) of */
/* the 1992 Explanatory Supplement. */
/* Called: */
/* CAL2JD Gregorian calendar to Julian Day number */
/* This revision: 2008 July 5 */
/* Copyright (C) 2008 IAU SOFA Review Board. See notes at end. */
/* ----------------------------------------------------------------------- */
/* Release year for this version of DAT */
/* Number of Delta(AT) changes (increase by 1 for each new leap second) */
/* Number of Delta(AT) expressions before leap seconds were introduced */
/* Dates (year, month) on which new Delta(AT) came into force */
/* New Delta(AT) which came into force on the given dates */
/* Reference dates (MJD) and drift rates (s/day), pre leap seconds */
/* Miscellaneous local variables */
/* Dates and Delta(AT)s */
/* Reference dates and drift rates */
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
/* Initialize the result to zero and the status to OK. */
da = 0.;
js = 0;
/* If invalid fraction of a day, set error status and give up. */
if (*fd < 0. || *fd >= 1.) {
js = -4;
goto L9000;
}
/* Convert the date into an MJD. */
cal2jd_(iy, im, id, &djm0, &djm, &js);
/* If invalid year, month, or day, give up. */
if (js < 0) {
goto L9000;
}
/* If pre-UTC year, set warning status and give up. */
if (*iy < idate[0]) {
js = 1;
goto L9000;
}
/* If suspiciously late year, set warning status but proceed. */
if (*iy > 2014) {
js = 1;
}
/* Combine year and month. */
m = *iy * 12 + *im;
/* Prepare to search the tables. */
more = TRUE_;
/* Find the most recent table entry. */
for (i__ = 39; i__ >= 1; --i__) {
if (more) {
is = i__;
more = m < idate[(i__ << 1) - 2] * 12 + idate[(i__ << 1) - 1];
}
/* L1: */
}
/* Get the Delta(AT). */
da = dats[is - 1];
/* If pre-1972, adjust for drift. */
if (is <= 14) {
da += (djm + *fd - drift[(is << 1) - 2]) * drift[(is << 1) - 1];
}
/* Return the Delta(AT) value and the status. */
L9000:
*deltat = da;
*j = js;
/* 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;
} /* dat_ */
|
