Procedure

   reordd_c ( Reorder a double precision array ) 

   void reordd_c ( ConstSpiceInt      * iorder,
                   SpiceInt             ndim,
                   SpiceDouble        * array  )

Abstract

   Reorder the elements of a double precision array according to a
   given order vector.

Required_Reading

   None.

Keywords

   ARRAY
   SORT

Brief_I/O

   VARIABLE  I/O  DESCRIPTION
   --------  ---  --------------------------------------------------
   iorder     I   Order vector to be used to re-order array.
   ndim       I   Dimension of array.
   array     I-O  Array to be re-ordered.

Detailed_Input

   iorder      is the order vector to be used to re-order the input
               array. The first element of iorder is the index of
               the first item of the re-ordered array, and so on.

               Note that the order imposed by reordd_c is not the
               same order that would be imposed by a sorting
               routine. In general, the order vector will have
               been created (by one of the order routines) for
               a related array, as illustrated in the example below.

   ndim        is the number of elements in the input array.

   array       on input, is an array containing some number of
               elements in unspecified order.

Detailed_Output

   array       on output, is the same array, with the elements
               re-ordered as specified by iorder.

Parameters

   None.

Exceptions

   1)  If ndim < 2, this routine executes a no-op. This case is
       not an error.

   2)  If memory cannot be allocated to create the temporary variable
       required for the execution of the underlying Fortran routine,
       the error SPICE(MALLOCFAILED) is signaled.

Files

   None.

Particulars

   reordd_c uses a cyclical algorithm to re-order the elements of
   the array in place. After re-ordering, element iorder[0] of
   the input array is the first element of the output array,
   element iorder[1] is the input array is the second element of
   the output array, and so on.

   The order vector used by reordd_c is typically created for
   a related array by one of the order routines, as shown in
   the example below.

Examples

   The numerical results shown for this example may differ across
   platforms. The results depend on the SPICE kernels used as
   input, the compiler and supporting libraries, and the machine
   specific arithmetic implementation.

   1) Sort four related arrays containing the names, masses,
      integer ID codes, and flags indicating whether they have
      a ring system, for a group of planets.


      Example code begins here.


      /.
         Program reordd_ex1
      ./
      #include <stdio.h>
      #include "SpiceUsr.h"

      int main( )
      {

         /.
         Local constants.
         ./
         #define NDIM         8
         #define STRLEN       8

         /.
         Local variables.
         ./

         SpiceInt             i;
         SpiceInt             iorder [NDIM];

         /.
         Set the arrays containing the names, masses (given as
         ratios to of Solar GM to barycenter GM), integer ID
         codes, and flags indicating whether they have a ring
         system.
         ./
         SpiceChar            names  [NDIM][STRLEN] = {
                                 "MERCURY", "VENUS",  "EARTH",  "MARS",
                                 "JUPITER", "SATURN", "URANUS", "NEPTUNE" };

         SpiceDouble          masses [NDIM] = {     22032.080,   324858.599,
                                                   398600.436,    42828.314,
                                                126712767.881, 37940626.068,
                                                  5794559.128,  6836534.065 };

         SpiceInt             codes  [NDIM] = { 199, 299, 399, 499,
                                                599, 699, 799, 899 };

         SpiceBoolean         rings  [NDIM] = { SPICEFALSE, SPICEFALSE,
                                                SPICEFALSE, SPICEFALSE,
                                                SPICETRUE,  SPICETRUE,
                                                SPICETRUE,  SPICETRUE  };

         /.
         Sort the object arrays by name.
         ./
         orderc_c ( STRLEN, names, NDIM,   iorder );

         reordc_c ( iorder, NDIM,  STRLEN, names  );
         reordd_c ( iorder, NDIM,  masses         );
         reordi_c ( iorder, NDIM,  codes          );
         reordl_c ( iorder, NDIM,  rings          );

         /.
         Output the resulting table.
         ./
         printf( " Planet   Mass(GMS/GM)  ID Code  Rings?\n" );
         printf( "-------  -------------  -------  ------\n" );

         for ( i = 0; i < NDIM; i++ )
         {

            printf( "%-7s %14.3f %8d %4d\n",
                    names[i], masses[i], codes[i], rings[i] );

         }

         return ( 0 );
      }


      When this program was executed on a Mac/Intel/cc/64-bit
      platform, the output was:


       Planet   Mass(GMS/GM)  ID Code  Rings?
      -------  -------------  -------  ------
      EARTH       398600.436      399    0
      JUPITER  126712767.881      599    1
      MARS         42828.314      499    0
      MERCURY      22032.080      199    0
      NEPTUNE    6836534.065      899    1
      SATURN    37940626.068      699    1
      URANUS     5794559.128      799    1
      VENUS       324858.599      299    0

Restrictions

   None.

Literature_References

   None.

Author_and_Institution

   N.J. Bachman        (JPL)
   J. Diaz del Rio     (ODC Space)
   E.D. Wright         (JPL)

Version

   -CSPICE Version 1.0.2, 27-AUG-2021 (JDR)

       Edited the header to comply with NAIF standard.
       Added complete code example.

   -CSPICE Version 1.0.1, 11-JAN-2003 (EDW)

       Trivial. Corrected 'Detailed_output' section
       header to 'Detailed_Output'.

   -CSPICE Version 1.0.0, 10-JUL-2002 (NJB)

Index_Entries

   reorder a d.p. array