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Index Page wncard_c

Table of contents

Procedure Abstract Required_Reading Keywords Brief_I/O Detailed_Input | Detailed_Output Parameters Exceptions Files Particulars Examples | Restrictions Literature_References Author_and_Institution Version Index_Entries

#### Procedure

       wncard_c ( Cardinality of a double precision window )

       SpiceInt wncard_c ( SpiceCell  * window )

#### Abstract

       Return the cardinality (number of intervals) of a double
       precision window.

#### Required_Reading

       WINDOWS

#### Keywords

       WINDOWS

#### Brief_I/O

       VARIABLE  I/O  DESCRIPTION
       --------  ---  --------------------------------------------------
       window     I   Input window

       The function returns the window cardinality of the window.

#### Detailed_Input

       window      is a window containing zero or more intervals.

                   `window' must be declared as a double precision SpiceCell.

                   CSPICE provides the following macro, which declares and
                   initializes the cell

                      SPICEDOUBLE_CELL        ( window, WINDOWSZ );

                   where WINDOWSZ is the maximum capacity of `window'.

#### Detailed_Output

       The function returns the cardinality of (number of intervals in)
       the input window.

#### Parameters

       None.

#### Exceptions

       1)  If the number of elements in `window' is not even, the error
           SPICE(INVALIDSIZE) is signaled by a routine in the call tree
           of this routine.

       2)  If the `window' cell argument has a type other than
           SpiceDouble, the error SPICE(TYPEMISMATCH) is signaled. The
           function returns the value 0.

#### Files

       None.

#### Particulars

       This function returns the value of card_c(window)/2.

#### 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) The following code example demonstrates how to insert an
          interval into an existing double precision SPICE window, and
          how to loop over all its intervals to extract their left and
          right points.

          Example code begins here.

          /.
             Program wncard_ex1
          ./
          #include <stdio.h>
          #include "SpiceUsr.h"

          int main()
          {

             /.
             Local parameters.
             ./
             #define WNSIZE          10

             /.
             Local variables.
             ./
             SpiceDouble              left;
             SpiceDouble              right;

             SPICEDOUBLE_CELL ( window,  WNSIZE );

             SpiceInt                 i;

             /.
             Validate the window with size WNSIZE and zero elements.
             ./
             wnvald_c ( WNSIZE, 0, &window );

             /.
             Insert the intervals

                [ 1, 3 ]  [ 7, 11 ]  [ 23, 27 ]

             into `window'.
             ./
             wninsd_c (  1.0,   3.0, &window );
             wninsd_c (  7.0,  11.0, &window );
             wninsd_c ( 23.0,  27.0, &window );

             /.
             Loop over the number of intervals in `window', output
             the `left' and `right' endpoints for each interval.
             ./
             for ( i=0; i<wncard_c(&window); i++)
             {
                wnfetd_c( &window, i, &left, &right );
                printf("Interval %d [%8.3f, %8.3f]\n", i, left, right );
             }

             return ( 0 );

          }

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

          Interval 0 [   1.000,    3.000]
          Interval 1 [   7.000,   11.000]
          Interval 2 [  23.000,   27.000]

#### Restrictions

       None.

#### Literature_References

       None.

#### Author_and_Institution

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

#### Version

       -CSPICE Version 1.0.1, 05-AUG-2021 (JDR)

           Edited the header to comply to NAIF standard. Created complete code
           example from code fragment and added example's problem statement.

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

           Completed -Exceptions section.

       -CSPICE Version 1.0.0, 21-AUG-2007 (EDW)

#### Index_Entries

       cardinality of a d.p. window

#### Link to routine wncard_c source file wncard_c.c

    Fri Dec 31 18:41:15 2021