Procedure

   wnelmd_c ( Element of a DP window ) 

   SpiceBoolean wnelmd_c ( SpiceDouble    point,
                           SpiceCell    * window )

Abstract

   Determine whether a point is an element of a double precision
   window.

Required_Reading

   WINDOWS

Keywords

   WINDOWS

Brief_I/O

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

   The function returns SPICETRUE if point is an element of window.

Detailed_Input

   point       is a point, which may or may not be contained in one of
               the intervals in `window'.

   window      is a SPICE 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 SPICETRUE if the input point is an element of
   the input window --- that is, if

      a(i)  <  point  <  b(i)
            -         -

   for some interval [ a(i), b(i) ] in `window' --- and returns SPICEFALSE
   otherwise.

Parameters

   None.

Exceptions

   1)  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.

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

Files

   None.

Particulars

   None.

Examples

   Let a contain the intervals

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

   Then the following expressions take the value SPICETRUE

      wnelmd_c ( 1.0, &window );
      wnelmd_c ( 9.0, &window );

   and the following expressions take the value SPICEFALSE

      wnelmd_c (  0.0, &window );
      wnelmd_c ( 13.0, &window );
      wnelmd_c ( 29.0, &window );

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, 25-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 #1 in -Exceptions section.

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

Index_Entries

   element of a d.p. window