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#include "erfa.h"
#include "erfam.h"
int eraJdcalf(int ndp, double dj1, double dj2, int iymdf[4])
/*
** - - - - - - - - - -
** e r a J d c a l f
** - - - - - - - - - -
**
** Julian Date to Gregorian Calendar, expressed in a form convenient
** for formatting messages: rounded to a specified precision.
**
** Given:
** ndp int number of decimal places of days in fraction
** dj1,dj2 double dj1+dj2 = Julian Date (Note 1)
**
** Returned:
** iymdf int[4] year, month, day, fraction in Gregorian
** calendar
**
** Returned (function value):
** int status:
** -1 = date out of range
** 0 = OK
** +1 = NDP not 0-9 (interpreted as 0)
**
** Notes:
**
** 1) The Julian Date is apportioned in any convenient way between
** the arguments dj1 and dj2. For example, JD=2450123.7 could
** be expressed in any of these ways, among others:
**
** dj1 dj2
**
** 2450123.7 0.0 (JD method)
** 2451545.0 -1421.3 (J2000 method)
** 2400000.5 50123.2 (MJD method)
** 2450123.5 0.2 (date & time method)
**
** 2) 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.
**
** 3) See also the function eraJd2cal.
**
** 4) The number of decimal places ndp should be 4 or less if internal
** overflows are to be avoided on platforms which use 16-bit
** integers.
**
** Called:
** eraJd2cal JD to Gregorian calendar
**
** Reference:
**
** Explanatory Supplement to the Astronomical Almanac,
** P. Kenneth Seidelmann (ed), University Science Books (1992),
** Section 12.92 (p604).
**
** This revision: 2021 May 11
**
** Copyright (C) 2013-2021, NumFOCUS Foundation.
** Derived, with permission, from the SOFA library. See notes at end of file.
*/
{
int j, js;
double denom, d1, d2, f1, f2, d, djd, f, rf;
/* Denominator of fraction (e.g. 100 for 2 decimal places). */
if ((ndp >= 0) && (ndp <= 9)) {
j = 0;
denom = pow(10.0, ndp);
} else {
j = 1;
denom = 1.0;
}
/* Copy the date, big then small. */
if (fabs(dj1) >= fabs(dj2)) {
d1 = dj1;
d2 = dj2;
} else {
d1 = dj2;
d2 = dj1;
}
/* Realign to midnight (without rounding error). */
d1 -= 0.5;
/* Separate day and fraction (as precisely as possible). */
d = ERFA_DNINT(d1);
f1 = d1 - d;
djd = d;
d = ERFA_DNINT(d2);
f2 = d2 - d;
djd += d;
d = ERFA_DNINT(f1 + f2);
f = (f1 - d) + f2;
if (f < 0.0) {
f += 1.0;
d -= 1.0;
}
djd += d;
/* Round the total fraction to the specified number of places. */
rf = ERFA_DNINT(f*denom) / denom;
/* Re-align to noon. */
djd += 0.5;
/* Convert to Gregorian calendar. */
js = eraJd2cal(djd, rf, &iymdf[0], &iymdf[1], &iymdf[2], &f);
if (js == 0) {
iymdf[3] = (int) ERFA_DNINT(f * denom);
} else {
j = js;
}
/* Return the status. */
return j;
/* Finished. */
}
/*----------------------------------------------------------------------
**
**
** Copyright (C) 2013-2021, 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.
**
*/