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Abstract
I/O
Examples
Particulars
Required Reading
Version
Index_Entries

Abstract


   CSPICE_WNDIFD places the difference of two double precision
   windows into a third window.

   For important details concerning this module's function, please refer to
   the CSPICE routine wndifd_c.

I/O

   
   Given:

      a,
      b   scalar, double precision windows, each of 
          which contains zero or more intervals. 

          The user must create 'a' and 'b' using 
          cspice_celld.

   the call:

      cspice_wndifd, a, b, c

   returns:

     c   the scalar, double precision output window, containing 
         the difference of 'a' and 'b'---every point contained 
         in 'a', but not contained in 'b'.
     
         The user must create 'c' using cspice_celld.

         'c' must be distinct from 'a' and 'b'. 

Examples


   Any numerical results shown for this example may differ between
   platforms as the results depend on the SPICE kernels used as input
   and the machine specific arithmetic implementation.

      ;; 
      ;; Create three cells each containing a double precision
      ;; 8-vector.
      ;;
      win1 = cspice_celld( 8 )
      win2 = cspice_celld( 8 )
      win3 = cspice_celld( 8 )

      ;;
      ;; Define two windows with three intervals.
      ;;
      darray = [ [ 1.d, 3.0], [ 7.0, 11.0], [23.0, 27.0] ]

      ;;
      ;; Add the window data to the cell.
      ;;
      for i=0, 2 do begin

         cspice_wninsd, darray[0,i], darray[1,i], win1

      endfor

      darray2 = [ [ 2.d, 6.0], [ 8.0, 10.0], [16.0, 18.0] ]

      ;;
      ;; Add the window data to the cell.
      ;;
      for i=0, 2 do begin

         cspice_wninsd, darray2[0,i], darray2[1,i], win2

      endfor

      ;;
      ;; Do the difference. 
      ;;
      cspice_wndifd, win1, win2, win3
       
      ;;
      ;; Calculate the number of intervals in the
      ;; return window 'win1'.
      ;;
      no_intervals = cspice_wncard(win3)

      ;;
      ;; Output the intervals.
      ;;
      for i= 0, (no_intervals -1 ) do begin

         cspice_wnfetd, win3, i, left, right
         print, left, right

      endfor

   IDL outputs:

      1.0000000       2.0000000
      7.0000000       8.0000000
      10.000000       11.000000
      23.000000       27.000000

Particulars


   The user must create any needed window structures with
   cspice_celld prior to use regardless of whether the routine
   uses the window as input or returns it as output.

Required Reading


   ICY.REQ
   CELLS.REQ
   WINDOWS.REQ

Version


   -Icy Version 1.0.2, 26-NOV-2007, EDW (JPL)

      Implemented use of cspice_wncard function to return 
      window cardinality.

   -Icy Version 1.0.1, 12-SEP-2006, EDW (JPL)

      Correct Required Reading citation CELL.REQ to CELLS.REQ.

   -Icy Version 1.0.0, 08-AUG-2004, EDW (JPL)

Index_Entries

 
   difference two d.p. windows 
 



Wed Apr  5 17:58:04 2017