SUBROUTINE IPOLATES(IP,IPOPT,KGDSI,KGDSO,MI,MO,KM,IBI,LI,GI, & NO,RLAT,RLON,IBO,LO,GO,IRET) !$$$ SUBPROGRAM DOCUMENTATION BLOCK ! ! $Revision: 71314 $ ! ! SUBPROGRAM: IPOLATES IREDELL'S POLATE FOR SCALAR FIELDS ! PRGMMR: IREDELL ORG: W/NMC23 DATE: 96-04-10 ! ! ABSTRACT: THIS SUBPROGRAM INTERPOLATES SCALAR FIELDS ! FROM ANY GRID TO ANY GRID (JOE IRWIN'S DREAM). ! ONLY HORIZONTAL INTERPOLATION IS PERFORMED. ! THE FOLLOWING INTERPOLATION METHODS ARE POSSIBLE: ! (IP=0) BILINEAR ! (IP=1) BICUBIC ! (IP=2) NEIGHBOR ! (IP=3) BUDGET ! (IP=4) SPECTRAL ! (IP=6) NEIGHBOR-BUDGET ! SOME OF THESE METHODS HAVE INTERPOLATION OPTIONS AND/OR ! RESTRICTIONS ON THE INPUT OR OUTPUT GRIDS, BOTH OF WHICH ! ARE DOCUMENTED MORE FULLY IN THEIR RESPECTIVE SUBPROGRAMS. ! THE GRIDS ARE DEFINED BY THEIR GRID DESCRIPTION SECTIONS ! (PASSED IN INTEGER FORM AS DECODED BY SUBPROGRAM W3FI63). ! THE CURRENT CODE RECOGNIZES THE FOLLOWING PROJECTIONS: ! (KGDS(1)=000) EQUIDISTANT CYLINDRICAL ! (KGDS(1)=001) MERCATOR CYLINDRICAL ! (KGDS(1)=003) LAMBERT CONFORMAL CONICAL ! (KGDS(1)=004) GAUSSIAN CYLINDRICAL ! (KGDS(1)=005) POLAR STEREOGRAPHIC AZIMUTHAL ! (KGDS(1)=203) ROTATED EQUIDISTANT CYLINDRICAL - E-STAGGER ! (KGDS(1)=205) ROTATED EQUIDISTANT CYLINDRICAL - B-STAGGER ! WHERE KGDS COULD BE EITHER INPUT KGDSI OR OUTPUT KGDSO. ! AS AN ADDED BONUS THE NUMBER OF OUTPUT GRID POINTS ! AND THEIR LATITUDES AND LONGITUDES ARE ALSO RETURNED. ! ON THE OTHER HAND, THE OUTPUT CAN BE A SET OF STATION POINTS ! IF KGDSO(1)<0, IN WHICH CASE THE NUMBER OF POINTS ! AND THEIR LATITUDES AND LONGITUDES MUST BE INPUT. ! FOR THE BUDGET APPROACH, A SUBSECTION OF THE GRID MAY ! BE OUTPUT BY SUBTRACTING KGDSO(1) FROM 255 AND PASSING ! IN THE LATITUDES AND LONGITUDES OF THE POINTS. ! INPUT BITMAPS WILL BE INTERPOLATED TO OUTPUT BITMAPS. ! OUTPUT BITMAPS WILL ALSO BE CREATED WHEN THE OUTPUT GRID ! EXTENDS OUTSIDE OF THE DOMAIN OF THE INPUT GRID. ! THE OUTPUT FIELD IS SET TO 0 WHERE THE OUTPUT BITMAP IS OFF. ! ! PROGRAM HISTORY LOG: ! 96-04-10 IREDELL ! ! USAGE: CALL IPOLATES(IP,IPOPT,KGDSI,KGDSO,MI,MO,KM,IBI,LI,GI, ! & NO,RLAT,RLON,IBO,LO,GO,IRET) ! ! INPUT ARGUMENT LIST: ! IP - INTEGER INTERPOLATION METHOD ! (IP=0 FOR BILINEAR; ! IP=1 FOR BICUBIC; ! IP=2 FOR NEIGHBOR; ! IP=3 FOR BUDGET; ! IP=4 FOR SPECTRAL; ! IP=6 FOR NEIGHBOR-BUDGET) ! IPOPT - INTEGER (20) INTERPOLATION OPTIONS ! (IP=0: (NO OPTIONS) ! IP=1: CONSTRAINT OPTION ! IP=2: (NO OPTIONS) ! IP=3: NUMBER IN RADIUS, RADIUS WEIGHTS, SEARCH RADIUS ! IP=4: SPECTRAL SHAPE, SPECTRAL TRUNCATION ! IP=6: NUMBER IN RADIUS, RADIUS WEIGHTS ...) ! KGDSI - INTEGER (200) INPUT GDS PARAMETERS AS DECODED BY W3FI63 ! KGDSO - INTEGER (200) OUTPUT GDS PARAMETERS ! MI - INTEGER SKIP NUMBER BETWEEN INPUT GRID FIELDS IF KM>1 ! OR DIMENSION OF INPUT GRID FIELDS IF KM=1 ! MO - INTEGER SKIP NUMBER BETWEEN OUTPUT GRID FIELDS IF KM>1 ! OR DIMENSION OF OUTPUT GRID FIELDS IF KM=1 ! KM - INTEGER NUMBER OF FIELDS TO INTERPOLATE ! IBI - INTEGER (KM) INPUT BITMAP FLAGS ! LI - LOGICAL*1 (MI,KM) INPUT BITMAPS (IF RESPECTIVE IBI(K)=1) ! GI - REAL (MI,KM) INPUT FIELDS TO INTERPOLATE ! NO - INTEGER NUMBER OF OUTPUT POINTS (ONLY IF KGDSO(1)<0) ! RLAT - REAL (NO) OUTPUT LATITUDES IN DEGREES (IF KGDSO(1)<0) ! RLON - REAL (NO) OUTPUT LONGITUDES IN DEGREES (IF KGDSO(1)<0) ! ! OUTPUT ARGUMENT LIST: ! NO - INTEGER NUMBER OF OUTPUT POINTS (ONLY IF KGDSO(1)>=0) ! RLAT - REAL (MO) OUTPUT LATITUDES IN DEGREES (IF KGDSO(1)>=0) ! RLON - REAL (MO) OUTPUT LONGITUDES IN DEGREES (IF KGDSO(1)>=0) ! IBO - INTEGER (KM) OUTPUT BITMAP FLAGS ! LO - LOGICAL*1 (MO,KM) OUTPUT BITMAPS (ALWAYS OUTPUT) ! GO - REAL (MO,KM) OUTPUT FIELDS INTERPOLATED ! IRET - INTEGER RETURN CODE ! 0 SUCCESSFUL INTERPOLATION ! 1 UNRECOGNIZED INTERPOLATION METHOD ! 2 UNRECOGNIZED INPUT GRID OR NO GRID OVERLAP ! 3 UNRECOGNIZED OUTPUT GRID ! 1X INVALID BICUBIC METHOD PARAMETERS ! 3X INVALID BUDGET METHOD PARAMETERS ! 4X INVALID SPECTRAL METHOD PARAMETERS ! ! SUBPROGRAMS CALLED: ! POLATES0 INTERPOLATE SCALAR FIELDS (BILINEAR) ! POLATES1 INTERPOLATE SCALAR FIELDS (BICUBIC) ! POLATES2 INTERPOLATE SCALAR FIELDS (NEIGHBOR) ! POLATES3 INTERPOLATE SCALAR FIELDS (BUDGET) ! POLATES4 INTERPOLATE SCALAR FIELDS (SPECTRAL) ! ! REMARKS: EXAMPLES DEMONSTRATING RELATIVE CPU COSTS. ! THIS EXAMPLE IS INTERPOLATING 12 LEVELS OF TEMPERATURES ! FROM THE 360 X 181 GLOBAL GRID (NCEP GRID 3) ! TO THE 93 X 68 HAWAIIAN MERCATOR GRID (NCEP GRID 204). ! THE EXAMPLE TIMES ARE FOR THE C90. AS A REFERENCE, THE CP TIME ! FOR UNPACKING THE GLOBAL 12 TEMPERATURE FIELDS IS 0.04 SECONDS. ! ! METHOD IP IPOPT CP SECONDS ! -------- -- ------------- ---------- ! BILINEAR 0 0.03 ! BICUBIC 1 0 0.07 ! BICUBIC 1 1 0.07 ! NEIGHBOR 2 0.01 ! BUDGET 3 -1,-1 0.48 ! SPECTRAL 4 0,40 0.22 ! SPECTRAL 4 1,40 0.24 ! SPECTRAL 4 0,-1 0.42 ! N-BUDGET 6 -1,-1 0.15 ! ! THE SPECTRAL INTERPOLATION IS FAST FOR THE MERCATOR GRID. ! HOWEVER, FOR SOME GRIDS THE SPECTRAL INTERPOLATION IS SLOW. ! THE FOLLOWING EXAMPLE IS INTERPOLATING 12 LEVELS OF TEMPERATURES ! FROM THE 360 X 181 GLOBAL GRID (NCEP GRID 3) ! TO THE 93 X 65 CONUS LAMBERT CONFORMAL GRID (NCEP GRID 211). ! ! METHOD IP IPOPT CP SECONDS ! -------- -- ------------- ---------- ! BILINEAR 0 0.03 ! BICUBIC 1 0 0.07 ! BICUBIC 1 1 0.07 ! NEIGHBOR 2 0.01 ! BUDGET 3 -1,-1 0.51 ! SPECTRAL 4 0,40 3.94 ! SPECTRAL 4 1,40 5.02 ! SPECTRAL 4 0,-1 11.36 ! N-BUDGET 6 -1,-1 0.18 ! ! ATTRIBUTES: ! LANGUAGE: FORTRAN 90 ! !$$$ IMPLICIT NONE ! INTEGER, INTENT(IN ) :: IP, IPOPT(20), KM, MI, MO INTEGER, INTENT(IN ) :: IBI(KM), KGDSI(200), KGDSO(200) INTEGER, INTENT(INOUT) :: NO INTEGER, INTENT( OUT) :: IRET, IBO(KM) ! LOGICAL*1, INTENT(IN ) :: LI(MI,KM) LOGICAL*1, INTENT( OUT) :: LO(MO,KM) ! REAL, INTENT(IN ) :: GI(MI,KM) REAL, INTENT(INOUT) :: RLAT(MO),RLON(MO) REAL, INTENT( OUT) :: GO(MO,KM) ! INTEGER :: K, N ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! BILINEAR INTERPOLATION IF(IP.EQ.0) THEN CALL POLATES0(IPOPT,KGDSI,KGDSO,MI,MO,KM,IBI,LI,GI,NO,RLAT,RLON,IBO,LO,GO,IRET) ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! BICUBIC INTERPOLATION ELSEIF(IP.EQ.1) THEN CALL POLATES1(IPOPT,KGDSI,KGDSO,MI,MO,KM,IBI,LI,GI,NO,RLAT,RLON,IBO,LO,GO,IRET) ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! NEIGHBOR INTERPOLATION ELSEIF(IP.EQ.2) THEN CALL POLATES2(IPOPT,KGDSI,KGDSO,MI,MO,KM,IBI,LI,GI,NO,RLAT,RLON,IBO,LO,GO,IRET) ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! BUDGET INTERPOLATION ELSEIF(IP.EQ.3) THEN CALL POLATES3(IPOPT,KGDSI,KGDSO,MI,MO,KM,IBI,LI,GI,NO,RLAT,RLON,IBO,LO,GO,IRET) ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! SPECTRAL INTERPOLATION ELSEIF(IP.EQ.4) THEN CALL POLATES4(IPOPT,KGDSI,KGDSO,MI,MO,KM,IBI,LI,GI,NO,RLAT,RLON,IBO,LO,GO,IRET) ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! NEIGHBOR-BUDGET INTERPOLATION ELSEIF(IP.EQ.6) THEN CALL POLATES6(IPOPT,KGDSI,KGDSO,MI,MO,KM,IBI,LI,GI,NO,RLAT,RLON,IBO,LO,GO,IRET) ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ! UNRECOGNIZED INTERPOLATION METHOD ELSE IF(KGDSO(1).GE.0) NO=0 DO K=1,KM IBO(K)=1 DO N=1,NO LO(N,K)=.FALSE. GO(N,K)=0. ENDDO ENDDO IRET=1 ENDIF ! - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - END SUBROUTINE IPOLATES