cmpmsg.f

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C> @file
C> @brief Specify the use of compression when writing BUFR messages

C> This subroutine is used to specify whether BUFR messages output
C> by future calls to [message-writing subroutines](@ref hierarchy) and
C> [subset-writing subroutines](@ref hierarchy) are to be compressed.
C>
C> @author J. Ator
C> @date 2005-03-09
C>
C> @param[in] CF   -- character*1: Flag indicating whether future BUFR
C>                    output messages are to be compressed
C>                     - 'N' = No (the default)
C>                     - 'Y' = Yes
C>
C> <p>This subroutine can be called at any time after the first call
C> to subroutine openbf(), and the specified value for CF will remain
C> in effect for all future calls to
C> [message-writing subroutines](@ref hierarchy) and
C> [subset-writing subroutines](@ref hierarchy) for all Fortran logical
C> units that are open for output within the application program, unless
C> a subsequent call is made to this subroutine to reset the value of
C> CF again.  If this subroutine is never called, a default value of
C> 'N' is used for CF, as set within subroutine bfrini().
C>
C> <p>When compression is activated, it is implemented using the
C> algorithm for data subset compression prescribed within the
C> [official WMO BUFR regulations](@ref manual).
C> Compression is most useful when the data subsets to be
C> compressed are devoid of any delayed replication, and when
C> there is minimal variation of corresponding data values among
C> different data subsets within the same BUFR message. Otherwise,
C> compression may provide little to no benefit, and which is why
C> it is not activated by default.
C>
C> <b>Program history log:</b>
C> | Date | Programmer | Comments |
C> | -----|------------|----------|
C> | 2005-03-09 | J. Ator  | Original author |
C>
      SUBROUTINE cmpmsg(CF)

      COMMON /msgcmp/ ccmf

      CHARACTER*128 bort_str
      CHARACTER*1   ccmf, cf

C-----------------------------------------------------------------------
C-----------------------------------------------------------------------

      CALL capit(cf)
      IF(cf.NE.'Y'.AND. cf.NE.'N') goto 900
      ccmf = cf 

C  EXITS
C  -----

      RETURN
900   WRITE(bort_str,'("BUFRLIB: CMPMSG - INPUT ARGUMENT IS ",A1,'//
     . '", IT MUST BE EITHER Y OR N")') cf
      CALL bort(bort_str)
      END