Procedure

   wnextd_c ( Extract the endpoints from a DP window ) 

   void wnextd_c ( SpiceChar     side,
                   SpiceCell   * window )

Abstract

   Extract the left or right endpoints from a double precision
   window.

Required_Reading

   WINDOWS

Keywords

   WINDOWS

Brief_I/O

   VARIABLE  I/O  DESCRIPTION
   --------  ---  --------------------------------------------------
   side       I   Extract left ('L') or right ('R') endpoints.
   window    I-O  Window to be extracted.

Detailed_Input

   side        indicates whether the left or right endpoints of the
               intervals in the window are to be extracted.

                  'L', 'l'       Left endpoints.
                  'R', 'r'       Right endpoints.

               If `side' is not recognized, the input window is not
               changed.

   window      on input, 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

   window      on output, is the collection of singleton intervals
               containing either the left or the right endpoints of the
               intervals in the original window.

Parameters

   None.

Exceptions

   1)  If the endpoint specification, `side', is not recognized, the
       error SPICE(INVALIDENDPNTSPEC) is signaled by a routine in the
       call tree of this routine.

   2)  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.

   3)  If the `window' cell argument has a type other than
       SpiceDouble, the error SPICE(TYPEMISMATCH) is signaled.

Files

   None.

Particulars

   This routine replaces every interval in the input window with
   the singleton interval containing one of the endpoints of the
   interval.

Examples

   Let window contain the intervals

      [ 1, 3 ]  [ 7, 11 ]  [ 23, 27 ]  [ 29, 29 ]

   Then the call

      wnextd_c (  'L', &window );

   produces the window

      [ 1, 1 ]  [ 7, 7 ]  [ 23, 23 ]  [ 29, 29 ]

   And the call

      wnextd_c ( 'R', &window );

   produces the window

      [ 3, 3 ]  [ 11, 11 ]  [ 27, 27 ]  [ 29, 29 ]

Restrictions

   None.

Literature_References

   None.

Author_and_Institution

   N.J. Bachman        (JPL)
   J. Diaz del Rio     (ODC Space)
   H.A. Neilan         (JPL)
   W.L. Taber          (JPL)
   I.M. Underwood      (JPL)

Version

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

       Edited the header to comply with NAIF standard.

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

       Added entry #2 in -Exceptions section.

   -CSPICE Version 1.0.0, 29-JUL-2002 (NJB) (HAN) (WLT) (IMU)

Index_Entries

   extract the endpoints from a d.p. window