CALL SEQUENCE...
       signag  GRID INPUT OUTPUT [ -kind VAL1 [VAL2] ]
 
 
      DESCRIPTION...
       signag - PRODUCES A GRID OF (-1,0,1) FROM (-,0,+) INPUT CARDS
 
 
      AUTHOR  - R.Laprise, DEC 06/83.
      LAST REVISION: $Header: Autres-corrections-d-usages-de-MAXW-NWDS-modifs-dans-GGSIGN-SIGNAG @ 2018-06-05 17:00:06 -0400 (dugas) $
 
 
      PURPOSE - READ INPUT RECORDS CONTAINING A TABLE OF "-", "0" OR "+"
                AND GENERATE STANDART CCRN (gaussian grid) FILES WITH
                CORRESPONDING FLOATING POINT VALUES.
 
 
      OUTPUT FILE...
       GRID = STANDART CCRN FILE IMAGE OF THE INPUT RECORDS. WILL
              CONTAIN RECORDS WITH -1.0, 0.0 OR 1.0 VALUES UPON EXIT.
              IF THE FILE EXISTS AT STARTUP, IT WILL BY DEFAULT BE
              OVER-WRITTEN (SEE THE KIND(2) COMMAND-LINE ARGUMENT).
              BUT EVEN THEN, IT'S FILE-TYPE WILL BE KEPT.
 
 
      INPUT PARAMETERS (FROM STD INPUT)...
 
       IBUF = STANDART CCRN 8 WORD LABEL
       CG   = SIGN INFO READ AND LATER TRANSLATED BY PROGRAM. IT IS READ ONE
              LATITUDE CIRCLE AT A TIME, EAST TO WEST AND FROM NORTH TO SOUTH.
              IF THERE ARE TO BE ILG LONGITUDES IN THE RESULTING CCC FILE,
              THERE SHOULD BE ILG-1 CHARACTERS/INPUT LINE. THE 0 LONGITUDE
              VALUE IS THEN USED FOR THE 360 LONGITUDE VALUE.
 
      INPUT PARAMETERS (FROM COMMAND-LINE ARGUMENTS)...
 
       KIND(1) = VERTICAL LEVEL TYPE. IT CAN ONLY BE USED WITH CMC/RPN STD
              FILES AND THEN LV1 AND LV2 ARE ASSUMED TO CONTAIN DECODED
              VALUES. FURTHERMORE, THIS PARAMETRE CAN ONLY BE SPECIFIED
              IN COMMAND-LINE MODE. THE CURRENTLY SUPPORTED VALUES ARE:
              'HAUTEUR'   , heights (m) with respect to sea level
              'SIGMA'     , classical terrain following (0.0 -> 1.0)
              'ETA'       , first version of the GEM ETA coordinate
              'PRESSION'  , pressure (mb)
              'ARBITRAIRE', arbitrary level (no units apply)
              'HAUTEURS'  , heights (M) with respect to the surface
              'HYBRIDE'   , hybrid GEM coordinate
              'THETA'     , potential temperature coordinate
              'GALCHEN'   , GalChen generalized coordinate
       KIND(2) = Append or over-write exiting GRID file ? The default
              is to over-write, unless KIND(2) is defined as 'APPEND'.
 
       READ( 5,5001 ) IBUF
 5000  FORMAT(6X,A4,I10,6X,A4,5I10)
 
 
      EXAMPLE OF INPUT LINES...
 
      GRID      3000      MASK      1000       129        64         0       -32
 
         01234567890123456789012345678901234567890123456789012345678901234567890
         1         2         3         4         5         6         7         8
 
 
      EXIT CONDITIONS...
        0 NO PROBLEMS
        1 ARRAY TO LARGE
        2 PREMATURE EOF ON INPUT
        3 PREMATURE EOF ON GRID