Merge commit 'd26ed8388f100a12996c0b92a98040ef2ba7fa8e' as 'ast'

1 files changed, 169 insertions, 0 deletions

diff --git a/ast/erfa/d2tf.c b/ast/erfa/d2tf.c
new file mode 100644
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+++ b/ast/erfa/d2tf.c
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+#include "erfa.h"
+
+void eraD2tf(int ndp, double days, char *sign, int ihmsf[4])
+/*
+**  - - - - - - - -
+**   e r a D 2 t f
+**  - - - - - - - -
+**
+**  Decompose days to hours, minutes, seconds, fraction.
+**
+**  Given:
+**     ndp     int     resolution (Note 1)
+**     days    double  interval in days
+**
+**  Returned:
+**     sign    char    '+' or '-'
+**     ihmsf   int[4]  hours, minutes, seconds, fraction
+**
+**  Notes:
+**
+**  1) The argument ndp is interpreted as follows:
+**
+**     ndp         resolution
+**      :      ...0000 00 00
+**     -7         1000 00 00
+**     -6          100 00 00
+**     -5           10 00 00
+**     -4            1 00 00
+**     -3            0 10 00
+**     -2            0 01 00
+**     -1            0 00 10
+**      0            0 00 01
+**      1            0 00 00.1
+**      2            0 00 00.01
+**      3            0 00 00.001
+**      :            0 00 00.000...
+**
+**  2) The largest positive useful value for ndp is determined by the
+**     size of days, the format of double on the target platform, and
+**     the risk of overflowing ihmsf[3].  On a typical platform, for
+**     days up to 1.0, the available floating-point precision might
+**     correspond to ndp=12.  However, the practical limit is typically
+**     ndp=9, set by the capacity of a 32-bit int, or ndp=4 if int is
+**     only 16 bits.
+**
+**  3) The absolute value of days may exceed 1.0.  In cases where it
+**     does not, it is up to the caller to test for and handle the
+**     case where days is very nearly 1.0 and rounds up to 24 hours,
+**     by testing for ihmsf[0]=24 and setting ihmsf[0-3] to zero.
+**
+**  Copyright (C) 2013-2016, NumFOCUS Foundation.
+**  Derived, with permission, from the SOFA library.  See notes at end of file.
+*/
+{
+   int nrs, n;
+   double rs, rm, rh, a, w, ah, am, as, af;
+
+
+/* Handle sign. */
+   *sign = (char) ( ( days >= 0.0 ) ? '+' : '-' );
+
+/* Interval in seconds. */
+   a = ERFA_DAYSEC * fabs(days);
+
+/* Pre-round if resolution coarser than 1s (then pretend ndp=1). */
+   if (ndp < 0) {
+      nrs = 1;
+      for (n = 1; n <= -ndp; n++) {
+          nrs *= (n == 2 || n == 4) ? 6 : 10;
+      }
+      rs = (double) nrs;
+      w = a / rs;
+      a = rs * ERFA_DNINT(w);
+   }
+
+/* Express the unit of each field in resolution units. */
+   nrs = 1;
+   for (n = 1; n <= ndp; n++) {
+      nrs *= 10;
+   }
+   rs = (double) nrs;
+   rm = rs * 60.0;
+   rh = rm * 60.0;
+
+/* Round the interval and express in resolution units. */
+   a = ERFA_DNINT(rs * a);
+
+/* Break into fields. */
+   ah = a / rh;
+   ah = ERFA_DINT(ah);
+   a -= ah * rh;
+   am = a / rm;
+   am = ERFA_DINT(am);
+   a -= am * rm;
+   as = a / rs;
+   as = ERFA_DINT(as);
+   af = a - as * rs;
+
+/* Return results. */
+   ihmsf[0] = (int) ah;
+   ihmsf[1] = (int) am;
+   ihmsf[2] = (int) as;
+   ihmsf[3] = (int) af;
+
+   return;
+
+}
+/*----------------------------------------------------------------------
+**  
+**  
+**  Copyright (C) 2013-2016, 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.
+**  
+*/