Procedure

   valid_c ( Validate a set ) 

   void valid_c (  SpiceInt      size,
                   SpiceInt      n,
                   SpiceCell   * a    )

Abstract

   Create a valid SPICE set from a SPICE Cell of any data type.

Required_Reading

   SETS

Keywords

   CELLS
   SETS

Brief_I/O

   VARIABLE  I/O  DESCRIPTION
   --------  ---  --------------------------------------------------
   size       I   Size (maximum cardinality) of the set.
   n          I   Initial no. of (possibly non-distinct) elements.
   a         I-O  Set to be validated.

Detailed_Input

   size        is the maximum cardinality (number of elements) of the set.
               `size' must not exceed the declared size of the set's data
               array.

   n           is the number of (possibly non-distinct) elements initially
               contained in the set's data array. `n' cannot be greater than
               the size of the set.

   a           is a SPICE set.

               On input, `a' contains `n' elements.

               `a' must be declared as a character, double precision or
               integer SpiceCell.

               CSPICE provides the following macros, which declare and
               initialize the cell

                  SPICECHAR_CELL          ( a, ASZ, AMLEN );
                  SPICEDOUBLE_CELL        ( a, ASZ );
                  SPICEINT_CELL           ( a, ASZ );

               where ASZ is the maximum capacity of `a' and AMLEN is the
               maximum length of any member in the character cell.

Detailed_Output

   a           on output, is a valid set created from the input set.

               To create a valid set, the elements are ordered, and duplicate
               elements are removed. The set's size and cardinality members
               are assigned their correct values.

               The set is ready for use with other set routines.

               When validating a character set, trailing blanks are not
               considered significant in process of sorting and removing
               duplicates. Trailing blanks are not preserved on output.

Parameters

   None.

Exceptions

   1)  If the size of the set is too small to hold the set BEFORE
       validation, the error SPICE(INVALIDSIZE) is signaled by a routine
       in the call tree of this routine. The set `a' is not modified.

   2)  If the cell argument does not have a recognized data type, the
       error SPICE(NOTSUPPORTED) is signaled.

   3)  If the cell argument is of type SpiceChar and the string length
       associated with it is non-positive or too short to be usable when
       constructing the equivalent SPICE character cell required by
       the wrapped SPICELIB routine, an error is signaled by a routine
       in the call tree of this routine.

Files

   None.

Particulars

   Because a set is ordered and contains distinct values, to create a
   set from a cell, it is necessary to sort the data array and remove
   duplicates. Once the array has been sorted, duplicate elements
   (adjacent after sorting) are removed. The size and cardinality of
   the set are initialized, and the set is ready to go.

   This routine is typically used to create a SPICE set from a SPICE
   cell whose array which has been initialized via calls the appndX_c
   routines, or through compile-time array initializers, or I/O
   statements. The resulting set can then be used with the other set
   routines.

   When a set is constructed from a large set of unordered values,
   it is far more efficient to append the values to the set and
   then validate the set, than to build up the set via calls to the
   insrtX_c routines. The latter sort the set and remove duplicates
   on each insertion.

   Because validation is done in place, there is no chance of
   overflow.

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) Build a double precision cell via a series of calls to appndd_c.
      Create a set from this set by calling valid_c.


      Example code begins here.


      /.
         Program valid_ex1
      ./
      #include <stdio.h>
      #include "SpiceUsr.h"

      int main()
      {
         /.
         Local parameters.

         SETSIZ is the maximum capacity of the set.
         ./
         #define SETSIZ          1000000

         /.
         INISIZ will be the initial number of elements in the set.
         ./
         #define INISIZ          10

         /.
         Declare the set.
         ./
         SPICEDOUBLE_CELL ( dpSet, SETSIZ );

         /.
         Other local variables.
         ./
         SpiceDouble             item;

         SpiceInt                i;

         /.
         Initialize the cell's data array.  We use bogus values to
         simplify the example.
         ./
         printf( "Input data array:\n" );
         for ( i = 0;  i < INISIZ;  i++ )
         {
            appndd_c (  (SpiceDouble)(-i),  &dpSet  );
            printf( "  %3.1f", (SpiceDouble)(-i) );
         }
         printf( "\n\n" );

         /.
         Validate the set.  The elements of the set will be arranged
         in increasing order after this call.
         ./
         valid_c ( SETSIZ, INISIZ, &dpSet );

         /.
         Output the elements of the set.
         ./
         printf( "Set elements:\n" );
         for ( i = 0; i < card_c( &dpSet ); i++ )
         {
            item  =  SPICE_CELL_ELEM_D( &dpSet, i );
            printf( "  %3.1f", item );
         }
         printf( "\n" );

         return ( 0 );
      }


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


      Input data array:
        0.0  -1.0  -2.0  -3.0  -4.0  -5.0  -6.0  -7.0  -8.0  -9.0

      Set elements:
        -9.0  -8.0  -7.0  -6.0  -5.0  -4.0  -3.0  -2.0  -1.0  0.0

Restrictions

   1)  String comparisons performed by this routine are Fortran-style:
       trailing blanks in the input sets are ignored. This gives
       consistent behavior with CSPICE code generated by the f2c
       translator, as well as with the Fortran SPICE Toolkit.

       Note that this behavior is not identical to that of the ANSI
       C library functions strcmp and strncmp.

Literature_References

   None.

Author_and_Institution

   N.J. Bachman        (JPL)
   C.A. Curzon         (JPL)
   J. Diaz del Rio     (ODC Space)
   W.L. Taber          (JPL)
   I.M. Underwood      (JPL)
   E.D. Wright         (JPL)

Version

   -CSPICE Version 1.1.0, 24-NOV-2021 (JDR)

       Changed the argument name "set" to "a" for consistency with other
       routines.

       Edited the header to comply with NAIF standard. Extended code example to
       generate outputs and inserted example's solution.

       Moved misplaced documentation from -Literature_References to
       -Restrictions.

       Extended description of argument "a" in -Detailed_Input to include
       type and preferred declaration method.

       Added entries #2 and #3 in -Exceptions section.

   -CSPICE Version 1.0.1, 12-NOV-2006 (EDW)

       Corrected minor typo, the -Literature_References header
       lacked the prefix "-".

   -CSPICE Version 1.0.0, 08-AUG-2002 (NJB) (CAC) (WLT) (IMU)

Index_Entries

   validate a set