C----------------------------------------------------------------------- SUBROUTINE POLATES0(IPOPT,KGDSI,KGDSO,MI,MO,KM,IBI,LI,GI, & NO,RLAT,RLON,IBO,LO,GO,IRET) C$$$ SUBPROGRAM DOCUMENTATION BLOCK C C SUBPROGRAM: POLATES0 INTERPOLATE SCALAR FIELDS (BILINEAR) C PRGMMR: IREDELL ORG: W/NMC23 DATE: 96-04-10 C C ABSTRACT: THIS SUBPROGRAM PERFORMS BILINEAR INTERPOLATION C FROM ANY GRID TO ANY GRID FOR SCALAR FIELDS. C NO OPTIONS ARE ALLOWED. C ONLY HORIZONTAL INTERPOLATION IS PERFORMED. C THE GRIDS ARE DEFINED BY THEIR GRID DESCRIPTION SECTIONS C (PASSED IN INTEGER FORM AS DECODED BY SUBPROGRAM W3FI63). C THE CURRENT CODE RECOGNIZES THE FOLLOWING PROJECTIONS: C (KGDS(1)=000) EQUIDISTANT CYLINDRICAL C (KGDS(1)=001) MERCATOR CYLINDRICAL C (KGDS(1)=003) LAMBERT CONFORMAL CONICAL C (KGDS(1)=004) GAUSSIAN CYLINDRICAL (SPECTRAL NATIVE) C (KGDS(1)=005) POLAR STEREOGRAPHIC AZIMUTHAL C (KGDS(1)=202) ROTATED EQUIDISTANT CYLINDRICAL (ETA NATIVE) C WHERE KGDS COULD BE EITHER INPUT KGDSI OR OUTPUT KGDSO. C AS AN ADDED BONUS THE NUMBER OF OUTPUT GRID POINTS C AND THEIR LATITUDES AND LONGITUDES ARE ALSO RETURNED. C ON THE OTHER HAND, THE OUTPUT CAN BE A SET OF STATION POINTS C IF KGDSO(1)<0, IN WHICH CASE THE NUMBER OF POINTS C AND THEIR LATITUDES AND LONGITUDES MUST BE INPUT. C INPUT BITMAPS WILL BE INTERPOLATED TO OUTPUT BITMAPS. C OUTPUT BITMAPS WILL ALSO BE CREATED WHEN THE OUTPUT GRID C EXTENDS OUTSIDE OF THE DOMAIN OF THE INPUT GRID. C THE OUTPUT FIELD IS SET TO 0 WHERE THE OUTPUT BITMAP IS OFF. C C PROGRAM HISTORY LOG: C 96-04-10 IREDELL C C USAGE: CALL POLATES0(IPOPT,KGDSI,KGDSO,MI,MO,KM,IBI,LI,GI, C & NO,RLAT,RLON,IBO,LO,GO,IRET) C C INPUT ARGUMENT LIST: C IPOPT - INTEGER (20) INTERPOLATION OPTIONS (NO OPTIONS) C KGDSI - INTEGER (200) INPUT GDS PARAMETERS AS DECODED BY W3FI63 C KGDSO - INTEGER (200) OUTPUT GDS PARAMETERS C (KGDSO(1)<0 IMPLIES RANDOM STATION POINTS) C MI - INTEGER SKIP NUMBER BETWEEN INPUT GRID FIELDS IF KM>1 C OR DIMENSION OF INPUT GRID FIELDS IF KM=1 C MO - INTEGER SKIP NUMBER BETWEEN OUTPUT GRID FIELDS IF KM>1 C OR DIMENSION OF OUTPUT GRID FIELDS IF KM=1 C KM - INTEGER NUMBER OF FIELDS TO INTERPOLATE C IBI - INTEGER (KM) INPUT BITMAP FLAGS C LI - LOGICAL*1 (MI,KM) INPUT BITMAPS (IF SOME IBI(K)=1) C GI - REAL (MI,KM) INPUT FIELDS TO INTERPOLATE C NO - INTEGER NUMBER OF OUTPUT POINTS (ONLY IF KGDSO(1)<0) C RLAT - REAL (NO) OUTPUT LATITUDES IN DEGREES (IF KGDSO(1)<0) C RLON - REAL (NO) OUTPUT LONGITUDES IN DEGREES (IF KGDSO(1)<0) C C OUTPUT ARGUMENT LIST: C NO - INTEGER NUMBER OF OUTPUT POINTS (ONLY IF KGDSO(1)>=0) C RLAT - REAL (MO) OUTPUT LATITUDES IN DEGREES (IF KGDSO(1)>=0) C RLON - REAL (MO) OUTPUT LONGITUDES IN DEGREES (IF KGDSO(1)>=0) C IBO - INTEGER (KM) OUTPUT BITMAP FLAGS C LO - LOGICAL*1 (MO,KM) OUTPUT BITMAPS (ALWAYS OUTPUT) C GO - REAL (MO,KM) OUTPUT FIELDS INTERPOLATED C IRET - INTEGER RETURN CODE C 0 SUCCESSFUL INTERPOLATION C 2 UNRECOGNIZED INPUT GRID OR NO GRID OVERLAP C 3 UNRECOGNIZED OUTPUT GRID C C SUBPROGRAMS CALLED: C GDSWIZ GRID DESCRIPTION SECTION WIZARD C (IJKGDS) RETURN FIELD POSITION FOR A GIVEN GRID POINT C POLFIXS MAKE MULTIPLE POLE SCALAR VALUES CONSISTENT C C ATTRIBUTES: C LANGUAGE: FORTRAN 77 C C$$$ CFPP$ EXPAND(IJKGDS) INTEGER IPOPT(20) INTEGER KGDSI(200),KGDSO(200) INTEGER IBI(KM),IBO(KM) LOGICAL*1 LI(MI,KM),LO(MO,KM) REAL GI(MI,KM),GO(MO,KM) REAL RLAT(MO),RLON(MO) REAL XPTS(MO),YPTS(MO) REAL WO(MO) INTEGER N11(MO),N21(MO),N12(MO),N22(MO) REAL W11(MO),W21(MO),W12(MO),W22(MO) PARAMETER(FILL=-9999.) C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - C COMPUTE NUMBER OF OUTPUT POINTS AND THEIR LATITUDES AND LONGITUDES. IRET=0 IF(KGDSO(1).GE.0) THEN CALL GDSWIZ(KGDSO, 0,MO,FILL,XPTS,YPTS,RLON,RLAT,NO,0,DUM,DUM) IF(NO.EQ.0) IRET=3 ENDIF C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - C LOCATE INPUT POINTS AND COMPUTE THEIR WEIGHTS CALL GDSWIZ(KGDSI,-1,NO,FILL,XPTS,YPTS,RLON,RLAT,NV,0,DUM,DUM) IF(IRET.EQ.0.AND.NV.EQ.0) IRET=2 DO N=1,NO XI=XPTS(N) YI=YPTS(N) IF(XI.NE.FILL.AND.YI.NE.FILL) THEN I1=XI I2=I1+1 J1=YI J2=J1+1 XF=XI-I1 YF=YI-J1 N11(N)=IJKGDS(I1,J1,KGDSI) N21(N)=IJKGDS(I2,J1,KGDSI) N12(N)=IJKGDS(I1,J2,KGDSI) N22(N)=IJKGDS(I2,J2,KGDSI) IF(MIN(N11(N),N21(N),N12(N),N22(N)).GT.0) THEN W11(N)=(1-XF)*(1-YF) W21(N)=XF*(1-YF) W12(N)=(1-XF)*YF W22(N)=XF*YF ELSE N11(N)=0 N21(N)=0 N12(N)=0 N22(N)=0 ENDIF ELSE N11(N)=0 N21(N)=0 N12(N)=0 N22(N)=0 ENDIF ENDDO C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - C INTERPOLATE WITH OR WITHOUT BITMAPS CMIC$ DO ALL AUTOSCOPE PRIVATE(WO) DO K=1,KM DO N=1,NO GO(N,K)=0. WO(N)=0. IF(N11(N).GT.0) THEN IF(IBI(K).EQ.0) THEN GO(N,K)=W11(N)*GI(N11(N),K)+W21(N)*GI(N21(N),K) & +W12(N)*GI(N12(N),K)+W22(N)*GI(N22(N),K) WO(N)=1 ELSE IF(LI(N11(N),K)) THEN GO(N,K)=GO(N,K)+W11(N)*GI(N11(N),K) WO(N)=WO(N)+W11(N) ENDIF IF(LI(N21(N),K)) THEN GO(N,K)=GO(N,K)+W21(N)*GI(N21(N),K) WO(N)=WO(N)+W21(N) ENDIF IF(LI(N12(N),K)) THEN GO(N,K)=GO(N,K)+W12(N)*GI(N12(N),K) WO(N)=WO(N)+W12(N) ENDIF IF(LI(N22(N),K)) THEN GO(N,K)=GO(N,K)+W22(N)*GI(N22(N),K) WO(N)=WO(N)+W22(N) ENDIF ENDIF ENDIF ENDDO IBO(K)=IBI(K) DO N=1,NO LO(N,K)=WO(N).GE.0.5 IF(LO(N,K)) THEN GO(N,K)=GO(N,K)/WO(N) ELSE IBO(K)=1 GO(N,K)=0. ENDIF ENDDO ENDDO IF(KGDSO(1).EQ.0) CALL POLFIXS(NO,MO,KM,RLAT,RLON,IBO,LO,GO) C - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - END