Procedure

   orderd_c ( Order of a double precision array ) 

   void orderd_c ( ConstSpiceDouble  * array,
                   SpiceInt            ndim,
                   SpiceInt          * iorder )

Abstract

   Determine the order of elements in a double precision array.

Required_Reading

   None.

Keywords

   ARRAY
   SORT

Brief_I/O

   VARIABLE  I/O  DESCRIPTION
   --------  ---  --------------------------------------------------
   array      I   Input array.
   ndim       I   Dimension of array.
   iorder     O   Order vector for array.

Detailed_Input

   array       is the input array.

   ndim        is the number of elements in the input array.

Detailed_Output

   iorder      is the order vector for the input array.
               iorder[0] is the index of the smallest element
               of array; iorder[1] is the index of the next
               smallest; and so on.

               The elements of iorder range from zero to ndim-1.

Parameters

   None.

Exceptions

   Error free.

   1)  A negative input dimension causes this routine to leave the
       output order vector unchanged.

Files

   None.

Particulars

   orderd_c finds the index of the smallest element of the input
   array. This becomes the first element of the order vector.
   The process is repeated for the rest of the elements.

   The order vector returned by orderd_c may be used by any of
   the reord* routines to sort sets of related arrays, as shown
   in the example below.

Examples

   In the following example, the order* and reord* routines are
   used to sort four related arrays (containing the names,
   masses, integer ID codes, and visual magnitudes for a group
   of satellites). This is representative of the typical use of
   these routines.

      #include "SpiceUsr.h"
           .
           .
           .
      /.
      Sort the object arrays by visual magnitude.
      ./

      orderd_c ( vmags,  n,  iorder );

      reordc_c ( iorder, n, namlen, names  );
      reordd_c ( iorder, n,         masses );
      reordi_c ( iorder, n,         codes  );
      reordd_c ( iorder, n,         vmags  );

Restrictions

   None.

Literature_References

   None.

Author_and_Institution

   N.J. Bachman        (JPL)
   J. Diaz del Rio     (ODC Space)
   I.M. Underwood      (JPL)

Version

   -CSPICE Version 1.0.2, 04-JUL-2021 (JDR)

       Edited the header to comply with NAIF standard.

   -CSPICE Version 1.0.1, 23-MAR-2010 (NJB)

       Header example was updated to show use of this routine.
       -Exceptions section was updated. Header sections were
       re-ordered.

   -CSPICE Version 1.0.0, 08-JUL-2002 (NJB) (IMU)

Index_Entries

   order of a d.p. array