Procedure

     WNUNID ( Union two DP windows )

     SUBROUTINE WNUNID ( A, B, C )

Abstract

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

Required_Reading

     WINDOWS

Keywords

     WINDOWS

Declarations

     IMPLICIT NONE

     INTEGER               LBCELL
     PARAMETER           ( LBCELL = -5 )

     DOUBLE PRECISION      A        ( LBCELL:* )
     DOUBLE PRECISION      B        ( LBCELL:* )
     DOUBLE PRECISION      C        ( LBCELL:* )

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.

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.

Parameters

     None.

Exceptions

     1)  If the union of the two windows results in an excess of
         elements, the error SPICE(WINDOWEXCESS) is signaled.

     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.

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)
     W.L. Taber         (JPL)
     I.M. Underwood     (JPL)

Version

    SPICELIB Version 1.2.0, 24-AUG-2021 (JDR) (NJB)

        Added IMPLICIT NONE statement.

        Edited the header to comply with NAIF standard. Fixed I/O type
        of argument C in $Brief_I/O table.

        Added entry #2 in $Exceptions section. Removed unnecessary
        entries in $Revisions section.

    SPICELIB Version 1.1.0, 08-FEB-1999 (WLT)

        The variable END was not initialized in the previous
        edition. It is now initialized to be the minimum of
        A(1) and B(1).

    SPICELIB Version 1.0.1, 10-MAR-1992 (WLT)

        Comment section for permuted index source lines was added
        following the header.

    SPICELIB Version 1.0.0, 31-JAN-1990 (WLT) (IMU) (HAN)