The following Fortran 77 program opens a file and reads vorticity and divergence (vo/d) spectral fields in GRIB format; it then calls INTUVP2 to create spectral U and /V fields. Because of the preliminary call to INTOUT, the U and /V fields are subsequently interpolated to grid-point fields with resolution 3 by 3 degrees without the need for a separate call to INTF. The function INTIN is not used here because the input fields are in GRIB format and are self-defining.
Subroutines PBOPEN, PBCLOSE, PBGRIB and PBWRITE handle pure binary input and output files.
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C C Copyright 2015 ECMWF. C C This software is licensed under the terms of the Apache Licence C Version 2.0 which can be obtained at http://www.apache.org/licenses/LICENSE-2.0. C C Unless required by applicable law or agreed to in writing, software C distributed under the License is distributed on an "AS IS" BASIS, C WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. C C In applying this licence, ECMWF does not waive the privileges and immunities C granted to it by virtue of its status as an intergovernmental organisation C nor does it submit to any jurisdiction. C PROGRAM SAMPLE4EXAMPLE_INTUVP2 C IMPLICIT NONE C Parameters INTEGER INTV JPGRIB ! GRIB REAL REALV size (up to 1/16 deg) INTEGER JPBYTES CHARACTER*20 CHARV! bytes/integer DIMENSIONPARAMETER INTV(4), REALV(4), CHARV(4) CJPGRIB = 33190420) #ifdef INTEGER_8 INTEGER JPGRIB, JPBYTES CPARAMETER (JPBYTES = 8) #else PARAMETER (JPGRIBJPBYTES = 70000004) C#endif C SetLocal JPBYTESvariables = 8 on a 64-bit machine. INTEGER PARAMETER INTV(JPBYTES = 4) C REAL INTEGER IVOGRIB (JPGRIB), IDVGRIB REALV(JPGRIB4) INTEGER IUGRIB (JPGRIB), IVGRIB (JPGRIB) CCHARACTER*20 CHARV CHARACTER*128 INFILE, OUTFILE, ARG INTEGER IUNIT1INLEN, IUNIT2OUTLEN, IRECU1, INLENGU2, IERRIRET, IRET,J,NARGS C CN ExternalsINTEGER IVOGRIB(JPGRIB), IDVGRIB(JPGRIB) INTEGER INTOUT, INTUVP2, IARGC IUGRIB(JPGRIB), IVGRIB(JPGRIB) C LOGICAL ISSAME CExternals CHARACTER*128INTEGER INFILEINTOUT, OUTFILEINTUVP2, CARG(4) C ********************************************************************** CIARGC C ------------------------------------------------------------------ C Pick up file names from command line. C INFILE = ' ' NARGSOUTFILE = IARGC()' ' IF( NARGSIARGC().LTEQ.4 ) THEN print*,'Usage: interpolation_example2 -i infile -o outfile' DO N = 1, 4, 2 STOP CALL GETARG(N,ARG) END IF (ARG.EQ.'-i') THEN DO 101 J=1,NARGS CALL GETARG(J,CARG(J)N+1,INFILE) 101 CONTINUE DO 102 J=1,NARGS,2 IF(CARG(J)ELSEIF (ARG.EQ.'-io') THEN INFILE=CARG(J CALL GETARG(N+1,OUTFILE) ENDIF ELSEIF(CARG(J).EQ.'-o') THEN ENDDO ENDIF CALL OUTFILE=CARG(J+1)CHECK( _ ELSEINDEX(INFILE,' ').EQ.1 .OR. INDEX(OUTFILE,' ').EQ.1, _ print*,'Usage: interpolationexample_example2intuvp2 -i infile -o outfile' ) INTV STOP= 0 REALV = 0. END IF 102CHARV = CONTINUE C ********************************************************************** '' C SetDefine outputthe grid interval for the output REALV(1) = 3.0 REALV(2) = 3.0 IRET = INTOUT('grid', INTV, REALV, CHARV) IFCALL CHECK( IRET .NE.0, 0'INTOUT (grid) THENfailed') REALV STOP 'grid setting INTOUT failed.' ENDIF C= 0. C Open input and output files. CALL PBOPEN(IUNIT1U1, INFILE, 'r', IERRIRET) IFCALL CHECK( IERR IRET.NE. 0 ) STOP, ' PBOPEN failed (r)') CALL PBOPEN(IUNIT2U2, OUTFILE, 'w', IERRIRET) IF ( IERR .NE. 0 ) STOP ' PBOPEN failed' CCALL CHECK(IRET.NE.0, 'PBOPEN failed (w)') C Start of loop on input vo/d pairs PRINT *, 'Start interpolation...' N = 0 220 CONTINUE N = N + 1 C Read vorticity.next vo/d pair CALL PBGRIB(IUNIT1U1, IVOGRIB, JPGRIB * JPBYTES, IRECINLEN, IERRIRET) IF ( IERR IRET.EQ. -1 ) GOTO 900THEN IF ( IERRIRET .NE.= 0 ) STOP ' PBGRIB failed forGOTO vorticity' C C290 ENDIF Read divergence.CALL CHECK(IRET.NE.0, 'PBGRIB failed (vo)') CALL PBGRIB(IUNIT1U1, IDVGRIB, JPGRIB * JPBYTES, IRECINLEN, IERRIRET) IF ( IERR IRET.EQ. -1 )) THEN IRET = 0 GOTO 900290 IF ( IERR ENDIF CALL CHECK(IRET.NE. 0 ), STOP ' PBGRIB failed for divergence' C(d)') C Create U and V Interpolate PRINT WRITE(*,*) 'Interpolate Createvo/d Upair and V.'#', N INLENGOUTLEN = JPGRIB IRET = INTUVP2(IVOGRIB, IDVGRIB, JPGRIB, IUGRIB, IVGRIB, INLENGOUTLEN) IFCALL CHECK( IRET .NE. 0 ) THEN WRITE(*,*) ' INTUVP failed.' STOP ENDIF C') C Write the new U and V productsu/v to file IF ( INLENG OUTLEN.GT. 0 ) THEN CALL PBWRITE(IUNIT2U2, IUGRIB, INLENG*JPBYTESOUTLEN, IERRIRET) IFCALL CHECK( IERR IRET.LT. (INLENG*JPBYTES) ) STOP ' OUTLEN,'PBWRITE failed (vo)') CALL PBWRITE(IUNIT2U2, IVGRIB, INLENG*JPBYTESOUTLEN, IERRIRET) IFCALL CHECK( IERR IRET.LT. (INLENG*JPBYTES) ) STOP ' OUTLEN,'PBWRITE failed (d)') ENDIF C C Closedown 900 CONTINUE C Loop back for next vo/d pair GOTO 220 C Close input290 and output files. CONTINUE CALL PBCLOSE(IUNIT1U1, IERRIRET) CALL PBCLOSE(IUNIT2U2, IERRIRET) PRINT *, 'Interpolated ', (N-1), ' vo/d pair(s).' END C ------------------------------------------------------------------ STOPSUBROUTINE CHECK(OOPS,MSG) IMPLICIT NONE LOGICAL OOPS CHARACTER MSG*(*) IF (OOPS) THEN PRINT *, MSG CALL EXIT(3) ENDIF END |