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|
C Copyright 1981-2007 ECMWF
C
C Licensed under the GNU Lesser General Public License which
C incorporates the terms and conditions of version 3 of the GNU
C General Public License.
C See LICENSE and gpl-3.0.txt for details.
C
INTEGER FUNCTION HRG2GG(L12PNT,OLDFLD,KGNOLD,AREA,POLE,
X KGNNEW,HGTYPE,NEWFLD,KSIZE,NUMPTS)
C
C---->
C**** HRG2GG
C
C Purpose
C -------
C
C This routine creates a rotated gaussian field from a reduced
C gaussian field using 12-point horizontal interpolation.
C
C
C Interface
C ---------
C
C IRET = HRG2GG(L12PNT,OLDFLD,KGNOLD,AREA,POLE,
C X KGNNEW,HGTYPE,NEWFLD,KSIZE,NUMPTS)
C
C
C Input parameters
C ----------------
C
C L12PNT - Chooses between 12-point and 4-point interpolation
C OLDFLD - Array of values from the old (reduced) gaussian field
C KGNOLD - Gaussian number for the old gaussian field
C AREA - Limits of area (N/W/S/E)
C POLE - Pole of rotation (lat/long)
C KGNNEW - Gaussian number for the new gaussian field
C HGTYPE - Type of new gaussian field
C 'F' = full, ie regular
C 'R' = reduced, ie quasi-regular
C KSIZE - The size of the array to fill with the regular
C lat/long field
C
C
C Output parameters
C -----------------
C
C NEWFLD - The array of values for the gaussian field
C NUMPTS - Number of points in the new gaussian field.
C
C Returns 0 if function successful, non-zero otherwise.
C
C
C Common block usage
C ------------------
C
C None
C
C
C Method
C ------
C
C Numbering of the points (I is the interpolation point):
C
C 13 5 6 14
C
C 7 1 2 8
C (I)
C 9 3 4 10
C
C 15 11 12 16
C
C The 12-point interpolation is not possible if either of the top
C two rows is above the original field northern latitude. The
C nearest neighbour is used if both rows are above, and a 4-pt
C bilinear interpolation is used if the top row is above.
C Similarily, if either of the bottom two rows is below the original
C field southern latitude.
C
C
C Externals
C ---------
C
C INTLOG - Log error message.
C JMALLOC - Dynamically allocate memory
C JFREE - Free dynamically allocated memory
C JGETGG - Reads the definition of a gaussian grid
C HGENGG - Calculates original lat/long (before rotation) for
C a rotated gaussian grid
C HNEI12 - Finds neighbours for points for interpolation
C HWTS12 - Calculates weightings for points for interpolation
C
C
C Reference
C ---------
C
C None.
C
C
C Comments
C --------
C
C None.
C
C
C Author
C ------
C
C J.D.Chambers ECMWF February 2001
C
C
C Modifications
C -------------
C
C None.
C
C----<
C -----------------------------------------------------------------|
C* Section 0. Definition of variables.
C -----------------------------------------------------------------|
C
IMPLICIT NONE
C
#include "parim.h"
#include "nifld.common"
#include "nofld.common"
C
C Parameters
C
INTEGER JNORTH, JSOUTH, JWEST, JEAST, JW_E, JN_S, JLAT, JLON
INTEGER JP12PT, JP4PT, JPNEARN
PARAMETER (JP12PT = 0)
PARAMETER (JP4PT = 1)
PARAMETER (JPNEARN = 2)
PARAMETER (JNORTH = 1 )
PARAMETER (JWEST = 2 )
PARAMETER (JSOUTH = 3 )
PARAMETER (JEAST = 4 )
PARAMETER (JW_E = 1 )
PARAMETER (JN_S = 2 )
PARAMETER (JLAT = 1 )
PARAMETER (JLON = 2 )
C
C Function arguments
C
LOGICAL L12PNT
INTEGER KGNOLD, KGNNEW, KSIZE, NUMPTS
REAL AREA(4), POLE(2), OLDFLD(*), NEWFLD(KSIZE)
CHARACTER*1 HGTYPE
C
C Local variables
C
INTEGER NEXT, LOOP, IRET, NLEN, NOPREV, NNPREV, NBYTES, NUMBER
INTEGER NEAREST
CHARACTER*1 NNTYPE
C
CHARACTER*12 YFLAG
LOGICAL LNEW, LFIRST, LVEGGY
INTEGER KSCHEME(1),NEIGH(12,1), KLA(1)
REAL PWTS(12,1)
POINTER (IPKSCHE, KSCHEME)
POINTER (IPNEIGH, NEIGH)
POINTER (IPKLA, KLA)
POINTER (IPPWTS, PWTS)
C
REAL PDLO0(1),PDLO1(1),PDLO2(1),PDLO3(1),PDLAT(1)
POINTER (IPPDLO0, PDLO0)
POINTER (IPPDLO1, PDLO1)
POINTER (IPPDLO2, PDLO2)
POINTER (IPPDLO3, PDLO3)
POINTER (IPPDLAT, PDLAT)
C
INTEGER IGG, IGGOLD, INN, INNOLD
INTEGER KPTS(1), KNPTS(1)
REAL GLATS(1), GNLATS(1)
INTEGER IOFFS(1)
POINTER (IPKPTS, KPTS)
POINTER (IPKNPTS, KNPTS)
POINTER (IPIOFFS, IOFFS)
POINTER (IPGLATS, GLATS)
POINTER (IPGNLATS, GNLATS)
C
INTEGER ILL, ILLOLD
REAL RLAT(1),RLON(1)
POINTER (IPRLAT, RLAT)
POINTER (IPRLON, RLON)
C
REAL OLD(1)
POINTER (IOLD, OLD)
C
DATA NOPREV/-1/, NNPREV/-1/, NNTYPE/' '/
DATA LNEW/.FALSE./, LFIRST/.TRUE./
DATA IGGOLD/-1/, INNOLD/-1/, ILLOLD/-1/, IOLD/-1/
C
SAVE LNEW, LFIRST
SAVE IPKSCHE, IPNEIGH, IPKLA, IPPWTS
SAVE IPPDLO0, IPPDLO1, IPPDLO2, IPPDLO3, IPPDLAT
SAVE NOPREV,NNPREV,NNTYPE
SAVE IGGOLD,INNOLD,IPKPTS,IPKNPTS,IPIOFFS,IPGLATS,IPGNLATS
SAVE ILLOLD, IPRLAT, IPRLON, IOLD
C
C Externals
C
INTEGER HNEI12, HGENGG
#ifdef POINTER_64
INTEGER*8 JMALLOC
#else
INTEGER JMALLOC
#endif
C
C -----------------------------------------------------------------|
C Section 1. Initialise.
C -----------------------------------------------------------------|
C
100 CONTINUE
C
HRG2GG = 0
C
CALL JDEBUG()
IF( L12PNT ) THEN
CALL INTLOG(JP_DEBUG,'HRG2GG: 12-pt interpolation',JPQUIET)
ELSE
CALL INTLOG(JP_DEBUG,'HRG2GG: 4-pt interpolation',JPQUIET)
ENDIF
C
CALL CHKPREC()
IF( LPREC )THEN
CALL INTLOG(JP_DEBUG,
X 'HRG2GG: precipitation threshold applied',JPQUIET)
ELSE
CALL INTLOG(JP_DEBUG,
X 'HRG2GG: precipitation threshold not applied',JPQUIET)
ENDIF
C Are we handling vegetation parameter
LVEGGY = (NITABLE.EQ.128).AND.
X ((NIPARAM.EQ.27).OR.
X (NIPARAM.EQ.28).OR.
X (NIPARAM.EQ.29).OR.
X (NIPARAM.EQ.30).OR.
X (NIPARAM.EQ.43) )
C Force nearest neighbour processing with env variable
CALL GETENV('NEAREST_NEIGHBOUR', YFLAG)
IF( YFLAG(1:1).EQ.'1' ) LVEGGY = .TRUE.
C Force nearest neighbour processing with INTOUT parameter
IF( LMETHOD ) LVEGGY = .TRUE.
IF( LVEGGY ) CALL INTLOG(JP_DEBUG,
X 'HRG2GG: nearest neighbour processing (vegetation)',JPQUIET)
C
C Dynamically allocate memory for old gaussian grid information.
C
IGG = KGNOLD*2
C
IF( IGG.GT.IGGOLD ) THEN
C
IF( IGGOLD.GT.0 ) CALL JFREE(IPKPTS)
C
NBYTES = (IGG*JPRLEN) + (2*IGG+1)*JPBYTES
C
IPKPTS = JMALLOC(NBYTES)
#ifdef hpR64
IPKPTS = IPKPTS/(1024*1024*1024*4)
#endif
IF( IPKPTS.EQ.0 ) THEN
CALL INTLOG(JP_ERROR,'HRG2GG: Memory allocation fail',JPQUIET)
HRG2GG = 1
GOTO 900
ENDIF
C
IPGLATS = IPKPTS + (IGG*JPBYTES)
IPIOFFS = IPGLATS + (IGG*JPRLEN)
C
IGGOLD = IGG
NOPREV = -1
C
ENDIF
C
C Build up offsets to start of each latitude in the original field.
C
IF( KGNOLD.NE.NOPREV ) THEN
CALL JGETGG(KGNOLD,'R',GLATS,KPTS,IRET)
IF( IRET.NE.0 ) THEN
CALL INTLOG(JP_ERROR,
X 'HRG2GG: JGETGG failed to get gaussian data',JPQUIET)
HRG2GG = 2
GOTO 900
ENDIF
C
IOFFS(1) = 1
DO LOOP = 2, (KGNOLD*2+1)
IOFFS(LOOP) = IOFFS(LOOP-1) + KPTS(LOOP-1)
ENDDO
C
C Allocate memory to hold the input field
C (in case OLDFLD and NEWFLD are the same arrays)
C
IF( IOLD.GT.0 ) CALL JFREE(IOLD)
C
NUMBER = (IOFFS(KGNOLD*2+1) - 1)
NBYTES = NUMBER * JPRLEN
C
IOLD = JMALLOC(NBYTES)
#ifdef hpR64
IOLD = IOLD/(1024*1024*1024*4)
#endif
IF( IOLD.EQ.0 ) THEN
CALL INTLOG(JP_ERROR,'HRG2GG: Memory allocation fail',JPQUIET)
HRG2GG = 3
GOTO 900
ENDIF
C
NOPREV = KGNOLD
ENDIF
C
C Preserve the input field
C
NUMBER = (IOFFS(KGNOLD*2+1) - 1)
DO LOOP = 1, NUMBER
OLD(LOOP) = OLDFLD(LOOP)
ENDDO
C
C -----------------------------------------------------------------|
C Section 2. Generate the lat/long points for the output grid
C -----------------------------------------------------------------|
C
200 CONTINUE
C
C
C Dynamically allocate memory for gaussian grid information.
C
INN = KGNNEW*2
C
IF( INN.GT.INNOLD ) THEN
C
IF( INNOLD.GT.0 ) CALL JFREE(IPKNPTS)
C
NBYTES = (INN*JPRLEN) + (INN*JPBYTES)
C
IPKNPTS = JMALLOC(NBYTES)
#ifdef hpR64
IPKNPTS = IPKNPTS/(1024*1024*1024*4)
#endif
IF( IPKNPTS.EQ.0 ) THEN
CALL INTLOG(JP_ERROR,'HRG2GG: Memory allocation fail',JPQUIET)
HRG2GG = 1
GOTO 900
ENDIF
C
IPGNLATS = IPKNPTS + (INN*JPBYTES)
C
INNOLD = INN
NNPREV = -1
ENDIF
C
IF( HGTYPE.EQ.'F' ) THEN
IF( (KGNNEW.NE.NNPREV).OR.(HGTYPE.NE.NNTYPE) ) THEN
NLEN = KGNNEW * KGNNEW * 8
CALL JGETGG(KGNNEW,'F',GNLATS,KNPTS,IRET)
IF( IRET.NE.0 ) THEN
CALL INTLOG(JP_ERROR,
X 'HRG2GG: JGETGG failed to get gaussian data',JPQUIET)
HRG2GG = 2
GOTO 900
ENDIF
NNPREV = KGNNEW
NNTYPE = HGTYPE
ENDIF
ELSE
IF( (KGNNEW.NE.NNPREV).OR.(HGTYPE.NE.NNTYPE) ) THEN
CALL JGETGG(KGNNEW,'R',GNLATS,KNPTS,IRET)
IF( IRET.NE.0 ) THEN
CALL INTLOG(JP_ERROR,
X 'HRG2GG: JGETGG failed to get gaussian data',JPQUIET)
HRG2GG = 2
GOTO 900
ENDIF
C
NLEN = 0
DO LOOP = 1, KGNNEW*2
NLEN = NLEN + KNPTS(LOOP)
ENDDO
NNPREV = KGNNEW
NNTYPE = HGTYPE
ENDIF
ENDIF
C
C Check that given array is big enough for the new field.
C
IF( NLEN.GT.KSIZE ) THEN
CALL INTLOG(JP_ERROR,'HRG2GG: Given array size = ',KSIZE)
CALL INTLOG(JP_ERROR,'HRG2GG: Required size = ',NLEN)
HRG2GG = 4
GOTO 900
ENDIF
C
C Dynamically allocate memory for lat/long arrays.
C
ILL = NLEN
IF( ILL.GT.ILLOLD ) THEN
C
LNEW = .TRUE.
C
IF( ILLOLD.GT.0 ) CALL JFREE(IPRLON)
C
NBYTES = 2*ILL*JPRLEN
C
IPRLON = JMALLOC(NBYTES)
#ifdef hpR64
IPRLON = IPRLON/(1024*1024*1024*4)
#endif
IF( IPRLON.EQ.0 ) THEN
CALL INTLOG(JP_ERROR,'HRG2GG: Memory allocation fail',JPQUIET)
HRG2GG = 5
GOTO 900
ENDIF
C
IPRLAT = IPRLON + (ILL*JPRLEN)
C
ILLOLD = ILL
C
ENDIF
C
IRET = HGENGG(AREA,POLE,KGNNEW,HGTYPE,KNPTS,GNLATS,ILL,
X RLAT,RLON,NUMPTS)
IF( IRET.NE.0 ) THEN
CALL INTLOG(JP_ERROR,
X 'HRG2GG: HGENGG failed to get lat/lon grid data',JPQUIET)
HRG2GG = 6
GOTO 900
ENDIF
C
C -----------------------------------------------------------------|
C Section 3. Find neighbours for each point for interpolation.
C -----------------------------------------------------------------|
C
300 CONTINUE
C
C Dynamically allocate memory for interpolation arrays.
C
IF( LNEW ) THEN
C
IF( .NOT.LFIRST ) CALL JFREE(IPPDLO0)
C
NBYTES = (17*JPRLEN + 14*JPBYTES) * ILL
C
IPPDLO0 = JMALLOC(NBYTES)
#ifdef hpR64
IPPDLO0 = IPPDLO0/(1024*1024*1024*4)
#endif
IF( IPPDLO0.EQ.0 ) THEN
CALL INTLOG(JP_ERROR,'HRG2GG: Memory allocation fail',JPQUIET)
HRG2GG = 7
GOTO 900
ENDIF
C
IPPDLO1 = IPPDLO0 + (ILL*JPRLEN)
IPPDLO2 = IPPDLO1 + (ILL*JPRLEN)
IPPDLO3 = IPPDLO2 + (ILL*JPRLEN)
IPPDLAT = IPPDLO3 + (ILL*JPRLEN)
IPPWTS = IPPDLAT + (ILL*JPRLEN)
IPKSCHE = IPPWTS + (12*ILL*JPRLEN)
IPKLA = IPKSCHE + (ILL*JPBYTES)
IPNEIGH = IPKLA + (ILL*JPBYTES)
C
LFIRST = .FALSE.
LNEW = .FALSE.
C
ENDIF
C
C Find neighbours.
C
IRET = HNEI12(L12PNT,NLEN,RLAT,RLON,KGNOLD,KPTS,GLATS,
X KSCHEME,PDLAT,PDLO0,PDLO1,PDLO2,PDLO3,KLA,NEIGH)
IF( IRET.NE.0 ) THEN
CALL INTLOG(JP_ERROR,
X 'HRG2GG: HNEI12 failed to find neighbours',JPQUIET)
HRG2GG = 8
GOTO 900
ENDIF
C
C -----------------------------------------------------------------|
C Section 4. Perform the 12-point horizontal interpolation.
C -----------------------------------------------------------------|
C
400 CONTINUE
C
C Setup the 12-point horizontal interpolation weights
C
CALL HWTS12
X (NLEN,KSCHEME,KLA,PDLAT,GLATS,PDLO0,PDLO1,PDLO2,PDLO3,NEIGH,
X PWTS)
C
C Calculate the interpolated grid point values
C
DO LOOP = 1, NLEN
IF( LVEGGY) THEN
NEAREST = 1
IF( PWTS( 2,LOOP).GT.PWTS(NEAREST,LOOP) ) NEAREST = 2
IF( PWTS( 3,LOOP).GT.PWTS(NEAREST,LOOP) ) NEAREST = 3
IF( PWTS( 4,LOOP).GT.PWTS(NEAREST,LOOP) ) NEAREST = 4
IF( PWTS( 5,LOOP).GT.PWTS(NEAREST,LOOP) ) NEAREST = 5
IF( PWTS( 6,LOOP).GT.PWTS(NEAREST,LOOP) ) NEAREST = 6
IF( PWTS( 7,LOOP).GT.PWTS(NEAREST,LOOP) ) NEAREST = 7
IF( PWTS( 8,LOOP).GT.PWTS(NEAREST,LOOP) ) NEAREST = 8
IF( PWTS( 9,LOOP).GT.PWTS(NEAREST,LOOP) ) NEAREST = 9
IF( PWTS(10,LOOP).GT.PWTS(NEAREST,LOOP) ) NEAREST =10
IF( PWTS(11,LOOP).GT.PWTS(NEAREST,LOOP) ) NEAREST =11
IF( PWTS(12,LOOP).GT.PWTS(NEAREST,LOOP) ) NEAREST =12
NEWFLD(LOOP) = OLD(NEIGH( NEAREST,LOOP))
ELSE
IF( KSCHEME(LOOP).EQ.JP12PT ) THEN
NEWFLD(LOOP) =
X OLD(NEIGH( 1,LOOP)) * PWTS( 1,LOOP) +
X OLD(NEIGH( 2,LOOP)) * PWTS( 2,LOOP) +
X OLD(NEIGH( 3,LOOP)) * PWTS( 3,LOOP) +
X OLD(NEIGH( 4,LOOP)) * PWTS( 4,LOOP) +
X OLD(NEIGH( 5,LOOP)) * PWTS( 5,LOOP) +
X OLD(NEIGH( 6,LOOP)) * PWTS( 6,LOOP) +
X OLD(NEIGH( 7,LOOP)) * PWTS( 7,LOOP) +
X OLD(NEIGH( 8,LOOP)) * PWTS( 8,LOOP) +
X OLD(NEIGH( 9,LOOP)) * PWTS( 9,LOOP) +
X OLD(NEIGH(10,LOOP)) * PWTS(10,LOOP) +
X OLD(NEIGH(11,LOOP)) * PWTS(11,LOOP) +
X OLD(NEIGH(12,LOOP)) * PWTS(12,LOOP)
C
ELSE IF( KSCHEME(LOOP).EQ.JP4PT ) THEN
NEWFLD(LOOP) =
X OLD(NEIGH( 1,LOOP)) * PWTS( 1,LOOP) +
X OLD(NEIGH( 2,LOOP)) * PWTS( 2,LOOP) +
X OLD(NEIGH( 3,LOOP)) * PWTS( 3,LOOP) +
X OLD(NEIGH( 4,LOOP)) * PWTS( 4,LOOP)
C
ELSE
DO NEXT = 1, 4
IF( NEIGH(NEXT,LOOP).NE.0 )
X NEWFLD(LOOP) = OLD(NEIGH(NEXT,LOOP))
ENDDO
C
ENDIF
ENDIF
ENDDO
C
C -----------------------------------------------------------------|
C Section 9. Return.
C -----------------------------------------------------------------|
C
900 CONTINUE
C
RETURN
END
|
