Abstract

   CSPICE_WNFETD fetches (returns) a particular interval from a
   double precision window.

I/O

   Given:

      window   SPICE window containing zero or more intervals.

               [2n,1] = size(window); double = class(window)

      n        index of a particular interval within the window.

               [1,1] = size(n); int32 = class(n)

               Indices range from 1 to `n', where `n' is the number of
               intervals in the window:

                  n = size(window,1)/2

   the call:

      [left, right] = cspice_wnfetd( window, n )

   returns:

      left,
      right    values defining the left and right endpoints of the nth
               interval in the input `window'.

               [1,1] = size(left);  int32 = class(left)
               [1,1] = size(right); int32 = class(right)

Parameters

   None.

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.

   1) Given a SPICE window of cardinality 6, fetch the left and right
      endpoints of each of its 3 interval intervals.

      Example code begins here.


      function wnfetd_ex1()

         %
         % Let `window' contain the intervals
         %
         window = [ [ 1; 3 ]; [ 7; 11 ]; [ 23; 27 ];  ];

         %
         % Output the intervals.  Number of intervals equals
         % half the number of elements for the Nx1 `window'.
         %
         disp( 'Window contents:')
         for i=1:cspice_wncard( window )

            [left, right] = cspice_wnfetd( window, i );
            fprintf( '%12.5f  %12.5f\n', left, right)

         end


      When this program was executed on a Mac/Intel/Octave6.x/64-bit
      platform, the output was:


      Window contents:
           1.00000       3.00000
           7.00000      11.00000
          23.00000      27.00000

Particulars

   None.

Exceptions

   1)  If `n' is less than one, the error SPICE(NOINTERVAL) is
       signaled by a routine in the call tree of this routine.

   2)  If the interval does not exist, i.e. n > cspice_card(window)/2, the
       error SPICE(NOINTERVAL) is signaled by a routine in the call
       tree of this routine.

   3)  The cardinality of the input `window' must be even. Left
       endpoints of stored intervals must be strictly greater than
       preceding right endpoints. Right endpoints must be greater
       than or equal to corresponding left endpoints. Invalid window
       data are not diagnosed by this routine and may lead to
       unpredictable results.

   4)  If any of the input arguments, `window' or `n', is undefined,
       an error is signaled by the Matlab error handling system.

   5)  If any of the input arguments, `window' or `n', is not of the
       expected type, or it does not have the expected dimensions and
       size, an error is signaled by the Mice interface.

Files

   None.

Restrictions

   None.

Required_Reading

   MICE.REQ
   WINDOWS.REQ

Literature_References

   None.

Author_and_Institution

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

Version

   -Mice Version 1.1.0, 13-AUG-2021 (EDW) (JDR)

       Edited the header and corrected error message format
       to comply with NAIF standard. Added example's problem statement.

       Added -Parameters, -Exceptions, -Files, -Restrictions,
       -Literature_References and -Author_and_Institution sections.

       Eliminated use of "lasterror" in rethrow.

       Removed reference to the function's corresponding CSPICE header from
       -Required_Reading section.

   -Mice Version 1.0.1, 11-JUN-2013 (EDW)

       -I/O descriptions edits to conform to Mice documentation format.

   -Mice Version 1.0.0, 24-JUL-2007 (EDW)

Index_Entries

   fetch an interval from a d.p. window