nemspecs.f

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C> @file
C> @brief Get the scale factor, reference value and bit width
C> associated with a specified occurrence of a Table B mnemonic.

C> Given a Table B mnemonic defined within a data subset, this
C> subroutine returns the scale factor, reference value and bit
C> width of a specified occurrence of that mnemonic within the
C> overall data subset definition, counting from the beginning
C> of the subset.
C>
C> <p>The values returned include the application of any Table C
C> operators (e.g. 2-01-YYY, 2-02-YYY, 2-03-YYY, 2-07-YYY,
C> 2-08-YYY) which may be in effect for the specified occurrence
C> of the mnemonic.
C>
C> @author J. Ator
C> @date 2014-10-02
C>
C> @param[in] LUNIT  - integer: Fortran logical unit number for
C>                     BUFR file
C> @param[in] NEMO   - character*(*): Table B mnemonic
C> @param[in] NNEMO  - integer: Ordinal occurrence of NEMO for
C>                     which information is to be returned,
C>                     counting from the beginning of the overall
C>                     subset definition
C> @param[out] NSCL  - integer: Scale factor in effect for
C>                     (NNEMO)th occurrence of NEMO
C> @param[out] NREF  - integer: Reference value in effect for
C>                     (NNEMO)th occurrence of NEMO
C> @param[out] NBTS  - integer: Bit width in effect for
C>                     (NNEMO)th occurrence of NEMO
C> @param[out] IRET  - integer: return code
C>                     - 0 = normal return
C>                     - -1 = NEMO could not be found, or some
C>                            other error occurred
C>
C> <p>A data subset must already be in scope within the BUFRLIB
C> internal arrays for LUNIT, either via a previous call to one
C> of the [subset-reading subroutines](@ref hierarchy)
C> (when reading BUFR data subsets) or via a previous call to one
C> of the [message-writing subroutines](@ref hierarchy)
C> (when writing BUFR data subsets).
C>
C> <b>Program history log:</b>
C> - 2014-10-02  J. Ator    -- Original version
C> - 2014-12-10  J. Ator    -- Use modules instead of COMMON blocks
C>
    SUBROUTINE nemspecs ( LUNIT, NEMO, NNEMO,
     .                nscl, nref, nbts, iret )

    USE moda_usrint
    USE moda_msgcwd
    USE moda_tables
    USE moda_nrv203

    CHARACTER*10  tagn

    CHARACTER*(*) nemo

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

    iret = -1

C   Get LUN from LUNIT.

    CALL status( lunit, lun, il, im )
    IF ( il .EQ. 0 ) RETURN
    IF ( inode(lun) .NE. inv(1,lun) ) RETURN

C   Starting from the beginning of the subset, locate the (NNEMO)th
C   occurrence of NEMO.

    CALL fstag( lun, nemo, nnemo, 1, nidx, ierfst )
    IF ( ierfst .NE. 0 ) RETURN

C   Confirm that NEMO is a Table B mnemonic.

    node = inv(nidx,lun)
    IF ( ( typ(node) .NE. 'NUM' ) .AND. ( typ(node) .NE. 'CHR' ) )
     .      RETURN

C   Get the scale factor, reference value and bit width, including
C   accounting for any Table C operators which may be in scope for
C   this particular occurrence of NEMO.

        iret = 0

    nscl = isc(node)
    nbts = ibt(node)
    nref = irf(node)

    IF ( nnrv .GT. 0 ) THEN

C     There are nodes containing redefined reference values (from
C     one or more 2-03-YYY operators) in the jump/link table, so we
C     need to check if this node is one of them.

      tagn = ' '
      CALL strsuc( nemo, tagn, ltn ) 
      IF ( ( ltn .LE. 0 ) .OR. ( ltn .GT. 8 ) ) RETURN

      DO jj = 1, nnrv
        IF ( ( node .NE. inodnrv(jj) ) .AND.
     .      ( tagn(1:8) .EQ. tagnrv(jj) ) .AND.
     .      ( node .GE. isnrv(jj) ) .AND.
     .      ( node .LE. ienrv(jj) ) ) THEN
          nref = nrv(jj)
          RETURN
        END IF
      END DO

    END IF

    RETURN
    END