C-----------------------------------------------------------------------
SUBROUTINE MAKGDS(IOPT,KGDS,GDS,LENGDS,IRET)
C$$$ SUBPROGRAM DOCUMENTATION BLOCK
C
C SUBPROGRAM: MAKGDS MAKE OR BREAK A GRID DESCRIPTION SECTION
C PRGMMR: IREDELL ORG: W/NMC23 DATE: 96-04-10
C
C ABSTRACT: THIS SUBPROGRAM MAKES OR BREAKS A GRID DESCRIPTION SECTION.
C IT CAN DO ONE OF THE FOLLOWING:
C (IOPT=-1) UNPACK A GDS INTO W3FI63 KGDS INTEGER FORM
C (IOPT=255) PACK A GDS FROM W3FI63 KGDS INTEGER FORM
C (0<IOPT<255) PACK A GDS FROM AN NCEP GRID IDENTIFICATION
C
C PROGRAM HISTORY LOG:
C 96-04-10 IREDELL
C
C USAGE: CALL MAKGDS(IOPT,KGDS,GDS,LENGDS,IRET)
C
C INPUT ARGUMENT LIST:
C IOPT - INTEGER OPTION
C IOPT=-1 TO UNPACK GDS INTO KGDS;
C IOPT=255 TO USE KGDS TO PACK GDS;
C 0<IOPT<255 NCEP GRID ID TO MAKE GDS AND KGDS.
C KGDS - INTEGER (200) W3FI63-STYLE UNPACKED GDS (IF IOPT=255)
C (ONLY FIRST 22 VALUES ARE ACCESSED IF KGDS(20)=255.)
C (SEE REMARKS BELOW FOR A DETAILED DESCRIPTION OF KGDS.)
C GDS - CHARACTER (400) GRID DEFINITION SECTION (IF IOPT=-1)
C
C OUTPUT ARGUMENT LIST:
C KGDS - INTEGER (200) W3FI63-STYLE UNPACKED GDS (IF IOPT<255)
C (ONLY FIRST 22 VALUES ARE ACCESSED IF KGDS(20)=255.)
C (SEE REMARKS BELOW FOR A DETAILED DESCRIPTION OF KGDS.)
C GDS - CHARACTER (400) GRID DEFINITION SECTION (IF IOPT>0)
C LENGDS - INTEGER LENGTH OF THE GDS (IF IOPT>0)
C IRET - INTEGER RETURN CODE
C 0 SUCCESSFUL
C 1 GRID REPRESENTATION TYPE NOT VALID
C 4 DATA REPRESENTATION TYPE NOT CURRENTLY ACCEPTABLE
C
C REMARKS: THE KGDS PARAMETERS ARE DESCRIBED BELOW
C AS COPIED FROM THE W3FI63 DOCBLOCK.
C (1) - DATA REPRESENTATION TYPE
C (19) - NUMBER OF VERTICAL COORDINATE PARAMETERS
C (20) - OCTET NUMBER OF THE LIST OF VERTICAL COORDINATE
C PARAMETERS
C OR
C OCTET NUMBER OF THE LIST OF NUMBERS OF POINTS
C IN EACH ROW
C OR
C 255 IF NEITHER ARE PRESENT
C (21) - FOR GRIDS WITH PL, NUMBER OF POINTS IN GRID
C (22) - NUMBER OF WORDS IN EACH ROW
C LATITUDE/LONGITUDE GRIDS
C (2) - N(I) NR POINTS ON LATITUDE CIRCLE
C (3) - N(J) NR POINTS ON LONGITUDE MERIDIAN
C (4) - LA(1) LATITUDE OF ORIGIN
C (5) - LO(1) LONGITUDE OF ORIGIN
C (6) - RESOLUTION FLAG (RIGHT ADJ COPY OF OCTET 17)
C (7) - LA(2) LATITUDE OF EXTREME POINT
C (8) - LO(2) LONGITUDE OF EXTREME POINT
C (9) - DI LATITUDINAL DIRECTION OF INCREMENT
C (10) - DJ LONGITUDINAL DIRECTION INCREMENT
C (11) - SCANNING MODE FLAG (RIGHT ADJ COPY OF OCTET 28)
C GAUSSIAN GRIDS
C (2) - N(I) NR POINTS ON LATITUDE CIRCLE
C (3) - N(J) NR POINTS ON LONGITUDE MERIDIAN
C (4) - LA(1) LATITUDE OF ORIGIN
C (5) - LO(1) LONGITUDE OF ORIGIN
C (6) - RESOLUTION FLAG (RIGHT ADJ COPY OF OCTET 17)
C (7) - LA(2) LATITUDE OF EXTREME POINT
C (8) - LO(2) LONGITUDE OF EXTREME POINT
C (9) - DI LATITUDINAL DIRECTION OF INCREMENT
C (10) - N - NR OF CIRCLES POLE TO EQUATOR
C (11) - SCANNING MODE FLAG (RIGHT ADJ COPY OF OCTET 28)
C (12) - NV - NR OF VERT COORD PARAMETERS
C (13) - PV - OCTET NR OF LIST OF VERT COORD PARAMETERS
C OR
C PL - LOCATION OF THE LIST OF NUMBERS OF POINTS IN
C EACH ROW (IF NO VERT COORD PARAMETERS
C ARE PRESENT
C OR
C 255 IF NEITHER ARE PRESENT
C POLAR STEREOGRAPHIC GRIDS
C (2) - N(I) NR POINTS ALONG LAT CIRCLE
C (3) - N(J) NR POINTS ALONG LON CIRCLE
C (4) - LA(1) LATITUDE OF ORIGIN
C (5) - LO(1) LONGITUDE OF ORIGIN
C (6) - RESOLUTION FLAG (RIGHT ADJ COPY OF OCTET 17)
C (7) - LOV GRID ORIENTATION
C (8) - DX - X DIRECTION INCREMENT
C (9) - DY - Y DIRECTION INCREMENT
C (10) - PROJECTION CENTER FLAG
C (11) - SCANNING MODE (RIGHT ADJ COPY OF OCTET 28)
C SPHERICAL HARMONIC COEFFICIENTS
C (2) - J PENTAGONAL RESOLUTION PARAMETER
C (3) - K " " "
C (4) - M " " "
C (5) - REPRESENTATION TYPE
C (6) - COEFFICIENT STORAGE MODE
C MERCATOR GRIDS
C (2) - N(I) NR POINTS ON LATITUDE CIRCLE
C (3) - N(J) NR POINTS ON LONGITUDE MERIDIAN
C (4) - LA(1) LATITUDE OF ORIGIN
C (5) - LO(1) LONGITUDE OF ORIGIN
C (6) - RESOLUTION FLAG (RIGHT ADJ COPY OF OCTET 17)
C (7) - LA(2) LATITUDE OF LAST GRID POINT
C (8) - LO(2) LONGITUDE OF LAST GRID POINT
C (9) - LATIT - LATITUDE OF PROJECTION INTERSECTION
C (10) - RESERVED
C (11) - SCANNING MODE FLAG (RIGHT ADJ COPY OF OCTET 28)
C (12) - LONGITUDINAL DIR GRID LENGTH
C (13) - LATITUDINAL DIR GRID LENGTH
C LAMBERT CONFORMAL GRIDS
C (2) - NX NR POINTS ALONG X-AXIS
C (3) - NY NR POINTS ALONG Y-AXIS
C (4) - LA1 LAT OF ORIGIN (LOWER LEFT)
C (5) - LO1 LON OF ORIGIN (LOWER LEFT)
C (6) - RESOLUTION (RIGHT ADJ COPY OF OCTET 17)
C (7) - LOV - ORIENTATION OF GRID
C (8) - DX - X-DIR INCREMENT
C (9) - DY - Y-DIR INCREMENT
C (10) - PROJECTION CENTER FLAG
C (11) - SCANNING MODE FLAG (RIGHT ADJ COPY OF OCTET 28)
C (12) - LATIN 1 - FIRST LAT FROM POLE OF SECANT CONE INTER
C (13) - LATIN 2 - SECOND LAT FROM POLE OF SECANT CONE INTER
C
C SUBPROGRAMS CALLED:
C FI633 EXTRACT INFO FROM GRIB-GDS
C R63W72 CONVERT W3FI63 PARMS TO W3FI72 PARMS
C W3FI71 MAKE ARRAY USED BY GRIB PACKER FOR GDS
C W3FI74 CONSTRUCT GRID DEFINITION SECTION (GDS)
C
C ATTRIBUTES:
C LANGUAGE: FORTRAN 77
C
C$$$
INTEGER KGDS(200)
CHARACTER GDS(400)
INTEGER KPTR(200),KPDS(200),IPDS(200),IGDS(200)
DATA KPTR/200*0/,KPDS/200*0/
C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
C UNPACK GDS INTO KGDS
IF(IOPT.EQ.-1) THEN
CALL FI633(GDS,KPTR,KGDS,IRET)
C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
C USE KGDS TO PACK GDS
ELSEIF(IOPT.EQ.255) THEN
CALL R63W72(KPDS,KGDS,IPDS,IGDS)
ICOMP=MOD(IGDS(8)/8,2)
CALL W3FI74(IGDS,ICOMP,GDS,LENGDS,NPTS,IRET)
C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
C USE NCEP GRID ID TO MAKE GDS AND KGDS
ELSEIF(IOPT.GT.0.AND.IOPT.LT.255) THEN
CALL W3FI71(IOPT,IGDS,IRET)
IF(IRET.EQ.0) THEN
ICOMP=MOD(IGDS(8)/8,2)
CALL W3FI74(IGDS,ICOMP,GDS,LENGDS,NPTS,IRET)
IF(IRET.EQ.0) CALL FI633(GDS,KPTR,KGDS,IRET)
ENDIF
ENDIF
C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
END