Procedure

   wnunid_c ( Union two DP windows ) 

   void wnunid_c ( SpiceCell   * a,
                   SpiceCell   * b,
                   SpiceCell   * c )

Abstract

   Place the union of two double precision windows into a third
   window.

Required_Reading

   WINDOWS

Keywords

   WINDOWS

Brief_I/O

   VARIABLE  I/O  DESCRIPTION
   --------  ---  --------------------------------------------------
   a,
   b          I   Input windows.
   c          O   Union of `a' and `b'.

Detailed_Input

   a,
   b           are SPICE windows, each of which contains zero or more
               intervals.

               `a' and `b' must be declared as double precision SpiceCells.

               CSPICE provides the following macros, which declare and
               initialize the cells

                  SPICEDOUBLE_CELL        ( a, ASZ );
                  SPICEDOUBLE_CELL        ( b, BSZ );

               where ASZ and BSZ are the maximum capacity of `a' and `b',
               respectively.

Detailed_Output

   c           is the output SPICE window, containing the union of `a'
               and `b' --- every point contained in `a', or in `b', or in
               both.

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

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

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

                  SPICEDOUBLE_CELL        ( c, CSZ );

               where CSZ is the maximum capacity of `c'.

Parameters

   None.

Exceptions

   1)  If the union of the two windows results in an excess of
       elements, the error SPICE(WINDOWEXCESS) is signaled by a
       routine in the call tree of this routine.

   2)  The cardinality of the input windows 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 any the `a', `b' or `c' cell arguments has a type other
       than SpiceDouble, the error SPICE(TYPEMISMATCH) is signaled.

Files

   None.

Particulars

   The union of two windows contains every point contained in the
   first window, or the second window, or both.

Examples

   Let a contain the intervals

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

   and b contain the intervals

         [ 2, 6 ]  [ 8, 10 ]  [ 16, 18 ]

   Then the union of a and b contains the intervals

         [ 1, 6 ]  [ 7, 11 ]  [ 16, 18 ]  [ 23, 27 ]

Restrictions

   None.

Literature_References

   None.

Author_and_Institution

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

Version

   -CSPICE Version 1.0.2, 24-AUG-2021 (JDR)

       Edited the header to comply with NAIF standard. Added entry #2
       in -Exceptions section.

       Extended description of arguments "a", "b" and "c" to include
       type and preferred declaration method.

   -CSPICE Version 1.0.1, 11-FEB-2013 (BVS)

       Corrected typo in Brief I/O section.

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

Index_Entries

   union two d.p. windows

Link to routine wnunid_c source file wnunid_c.c