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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
LOGICAL FUNCTION JACOBI(DATA,NM,W,SLAT)
C
C---->
C**** JACOBI
C
C Purpose
C -------
C
C Rotates spectral fields by latitude.
C
C
C Interface
C ---------
C
C IRET = JACOBI(DATA,NM,W,SLAT)
C
C Input
C -----
C
C NM - Triangular truncation number of the field.
C DATA - Linear array of REAL*8s of size (NM+1)*(NM+2)
C holding the field.
C W - Work array of REAL*8s of size (NM+1)*(NM+2).
C SLAT - Rotation angle (degrees, REAL*8)
C (degrees, negative => rotate counter-clockwise about the
C new Z-axis).
C
C
C Output
C ------
C
C DATA - The transformed field.
C
C Function returns .FALSE. if data cannot be transformed.
C
C
C Method
C ------
C
C See reference paper below.
C
C A file of rotation coefficients is opened corresponding to
C the triangular truncation NM and the rotation angle SLAT:
C
C $PP_ROT_DIR/rot_coefs_Tttt_nnnnnnnnn
C (or $SCRATCH/rot_coefs_Tttt_nnnnnnnnn,
C or $PWD/rot_coefs_Tttt_nnnnnnnnn)
C
C where:
C ttt = triangular truncation
C nnnnnnnnn = SLAT*100000,
C or
C $PP_ROT_DIR/rot_coefs_Tttt_Mnnnnnnnn
C (or $SCRATCH/rot_coefs_Tttt_Mnnnnnnnn,
C or $PWD/rot_coefs_Tttt_Mnnnnnnnn)
C
C where:
C ttt = triangular truncation
C nnnnnnnn = -SLAT*100000 if SLAT is negative.
C
C If the file does not exist it is created. During creation, the
C filename is ROTpppppp_Tttt_nnnnnnnnn, where pppppp is the current
C process ID.
C
C The file of rotation coefficients is UNLINKed by the process after
C being opened for reading. This causes the file to be removed when
C the process terminates.
C
C
C Externals
C ---------
C
C INTLOG - Logs messages.
C INTLOGR - Logs messages.
C GETENV - to get environment variable data.
C GETPID - to get the current process ID.
C RENAME - to change a filename.
C UNLINK - to remove a file.
C
C
C Author
C ------
C
C R.McGrath and P.Lynch HIRLAM
C
C
C Reference.
C ----------
C
C "Spectral synthesis on rotated and regular grids"
C by P.Lynch and R.McGrath (Irish Meteorological Service).
C
C
C----<
C---------------------------------------------------------------------
C
IMPLICIT NONE
C
#include "jparams.h"
#include "parim.h"
C
C Function arguments.
C
REAL*8 DATA, W
DIMENSION DATA(*), W(*)
INTEGER NM
REAL*8 SLAT
C
C Parameters.
C
REAL*8 EPS
PARAMETER(EPS = 1.0E-10)
INTEGER JPNM_MAX
PARAMETER( JPNM_MAX = 640 )
INTEGER NPBYTES
PARAMETER( NPBYTES = 8 )
C
C Local variables.
C
#ifndef REAL_8
REAL SSLAT
#endif
LOGICAL LFOR
INTEGER I, ISKIP, J, N, MM, K, IEND, IPLUG, IPID
INTEGER NN, M, NDEX
REAL*8 SIMAG, S, TEMP, DSLAT
REAL*8 RAD, TANB, SINB, COSB, Q, RNKN, BNKN, SQNN
REAL*8 SQNN1, SQ2N, PKN, PK1N, RNKN1, SREAL ,RNK0, RNK1
REAL*8 WISQR(JPNM_MAX)
REAL*8 WIB(JPNM_MAX)
REAL*8 WIR(JPNM_MAX)
REAL*8 WIDAT(2*JPNM_MAX)
CHARACTER*256 FILEDUM
CHARACTER*256 FILENAME
CHARACTER*24 COEFILE
DATA COEFILE/'rot_coefs_Tnnn_nnnnnnnnn'/
INTEGER FIRST, IUNIT, IRET, ILAT, OLDLAT, OLDTRUN, IOFFSET
INTEGER IFSIZE
INTEGER NMP1TM, MINUS1
DATA FIRST/0/, OLDLAT/10000000/, OLDTRUN/0/
SAVE FIRST, IUNIT, ILAT, OLDLAT, OLDTRUN, FILENAME, COEFILE
C
C Externals
C
#ifndef gfortran
INTEGER GETPID, UNLINK, RENAME
EXTERNAL GETPID, UNLINK, RENAME
#endif
C
C Statement function
C
REAL*8 A, B
LOGICAL ABSCHK
ABSCHK(A,B) = (ABS(A-B) .LT. EPS*(ABS(A) + ABS(B)))
C
C W array: 1 -> (NM+1)*(NM+2) for PMN/SQRT(2*N+1) values.
C
C RNKM values in WIR (for M>0),
C in WIB (M<0).
C Array of temporary SQRT values in WISQR, and
C temporary transformed data in WIDAT
C
C ------------------------------------------------------------------
C* Section 1. Initialise
C ------------------------------------------------------------------
C
100 CONTINUE
C
JACOBI = .FALSE.
C
CALL INTLOG(JP_DEBUG,'JACOBI: truncation = ', NM)
#ifndef REAL_8
SSLAT = SNGL(SLAT)
CALL INTLOGR(JP_DEBUG,'JACOBI: rotation angle = ', SSLAT)
#else
CALL INTLOGR(JP_DEBUG,'JACOBI: rotation angle = ', SLAT)
#endif
C
C Exit immediately if rotation angle is zero.
C
IF (ABS(SLAT).LT.EPS) THEN
JACOBI = .TRUE.
GOTO 999
ENDIF
C
C Change to radians.
C
RAD = 180.0/PPI
DSLAT = SLAT/RAD
TANB = TAN(DSLAT/(2.0))
SINB = SIN(DSLAT)
COSB = COS(DSLAT)
Q = SQRT(2.0)/2.0
C
C ------------------------------------------------------------------
C* Section 2. Generate PMN/SQRT(2*N+1) values in W.
C ------------------------------------------------------------------
C
200 CONTINUE
C
W(1) = 1.0
W(2) = COSB
C
ISKIP = NM + 1
DO 210 I = 1,ISKIP
W(1+ISKIP*I) = W(1+ISKIP*I-ISKIP)*SINB*
X SQRT(DBLE(2*I-1)/DBLE(2*I))
W(1+ISKIP*I+1) = COSB*DSQRT(DBLE(2*I+1))*W(1+ISKIP*I)
210 CONTINUE
C
DO 220 I = 2,ISKIP-1
C
DO 215 J = 0,ISKIP-I+1
W(I+J*ISKIP+1) = COSB*DSQRT(DBLE((2*I+2*J-1)*(2*I+2*J-1))/
X DBLE((I+2*J)*I))*W(I+J*ISKIP)
X - DSQRT(DBLE((I-1)*(I+2*J-1))/
X DBLE((I+2*J)*I))*W(I+J*ISKIP-1)
215 CONTINUE
C
220 CONTINUE
C
C ------------------------------------------------------------------
C* Section 3. Generate the rotation coefficients RNKM.
C ------------------------------------------------------------------
C
300 CONTINUE
C
C Generate the rotation coefficients RNKM (K = M dashed in note)
C and store in W. For K = 0 special case.
C
C PMN = W(M*(NM+1) + (N-M+1))
C
C Hold the input latitude and check if it is the same as the one
C used the last time through
C
ILAT = NINT(SLAT*100000)
IF( (ILAT.EQ.OLDLAT).AND.(OLDTRUN.EQ.NM) ) THEN
C
C Rewind the existing open coefficients file.
C
CALL PBSEEK(IUNIT,0,0,IRET)
IF( IRET.NE.0 ) THEN
CALL INTLOG(JP_FATAL,'JACOBI: Rewind failed.',JPQUIET)
CALL PBCLOSE(IUNIT,IRET)
JACOBI = .FALSE.
GOTO 999
ENDIF
C
ELSE
C
C A different coefficients file is needed.
C
IF( FIRST.NE.0 ) THEN
CALL PBCLOSE(IUNIT,IRET)
IF( IRET.NE.0 ) THEN
CALL INTLOG(JP_ERROR,'JACOBI: PBCLOSE failed.',JPQUIET)
JACOBI = .FALSE.
ENDIF
ENDIF
OLDLAT = ILAT
OLDTRUN = NM
C
C Setup the file name: rot_coefs_Tnnn_nnnnnnnnn
C (Path is given by PP_ROT_DIR, SCRATCH, or PWD.)
C
CALL GETENV('PP_ROT_DIR',FILENAME)
IOFFSET = INDEX(FILENAME,' ')
IF( IOFFSET.EQ.1) THEN
CALL GETENV('SCRATCH',FILENAME)
IOFFSET = INDEX(FILENAME,' ')
IF( IOFFSET.EQ.1) THEN
FILENAME = '.'
ENDIF
ENDIF
C
IOFFSET = INDEX(FILENAME,' ')
WRITE(COEFILE(12:14),'(I3.3)') NM
IF( ILAT.GE.0) THEN
WRITE(COEFILE(16:),'(I9.9)') ILAT
ELSE
COEFILE(16:) = 'M'
WRITE(COEFILE(17:),'(I8.8)') -ILAT
ENDIF
FILENAME = FILENAME(1:IOFFSET-1) // '/' // COEFILE
C
FILEDUM = FILENAME
IPID = GETPID()
IF( IPID.LT.0 ) THEN
CALL INTLOG(JP_FATAL,'JACOBI: GETPID failed',JPQUIET)
JACOBI = .FALSE.
GOTO 999
ENDIF
IOFFSET = INDEX(FILENAME,' ')
IPLUG = INDEX(FILENAME,'rot_coefs') + 3
WRITE(FILEDUM(IPLUG:IPLUG+5),'(I6.6)') IPID
C
C Try to open the file to see if it already exists
C
CALL PBOPEN(IUNIT,FILENAME(1:IOFFSET-1),'r',IRET)
IF( IRET.NE.0 ) THEN
CALL INTLOG(JP_DEBUG,'JACOBI: PBOPEN for read failed',JPQUIET)
CALL INTLOG(JP_DEBUG,'JACOBI: Non-existent file:',JPQUIET)
C
C Set flag to show file does not exist
C
FIRST = 0
C
ELSE
C
C File exists
C
FIRST = 1
C
C Unlink the file so it disappears on close
C
FIRST = 1
IRET = UNLINK(FILENAME(1:IOFFSET-1))
IF( IRET.NE.0 ) THEN
CALL INTLOG(JP_FATAL,'JACOBI: UNLINK failed',JPQUIET)
JACOBI = .FALSE.
GOTO 999
ENDIF
C
C Calculate the coefficients file size and check file is
C the correct size (coefficients are REAL*8)
C
IFSIZE = 8*(NM*(2*NM*NM + 9*NM +13)/3)
CALL PBSEEK(IUNIT,0,2,IRET)
IF( IRET.LT.0 ) THEN
CALL INTLOG(JP_FATAL,'JACOBI: PBSEEK failed.',JPQUIET)
CALL PBCLOSE(IUNIT,IRET)
JACOBI = .FALSE.
GOTO 999
ENDIF
C
IF( IFSIZE.NE.IRET) THEN
CALL INTLOG(JP_FATAL,
X 'JACOBI: Coefficients file size incorrect = ',IRET)
CALL INTLOG(JP_FATAL,
X 'JACOBI: Expected file size is = ',IFSIZE)
CALL PBCLOSE(IUNIT,IRET)
JACOBI = .FALSE.
GOTO 999
ENDIF
C
C Rewind the coefficients file.
C
CALL PBSEEK(IUNIT,0,0,IRET)
IF( IRET.NE.0 ) THEN
CALL INTLOG(JP_FATAL,'JACOBI: Rewind failed.',JPQUIET)
CALL PBCLOSE(IUNIT,IRET)
JACOBI = .FALSE.
GOTO 999
ENDIF
ENDIF
ENDIF
C
DO 530 N = 1,NM
RNKN = (0.5*(1.0 + COSB))**N
BNKN = (0.5*(1.0 - COSB))**N
SQNN = DSQRT(DBLE((N+1)*N))
SQNN1 = SQNN*SINB
SQ2N = DSQRT(2.0/DBLE(N))/SINB
C
C Save SQRTS.
C
DO 325 MM = 0,N
WISQR(MM+1) = DSQRT(DBLE((N+MM)*(N-MM+1)))*SINB
325 CONTINUE
C
NN = 1
C
C Generate RNKM, M = 0 to N.
C
DO 490 K = N,0,-1
C
C Generate the coefficients file if it doesn't exist
C
IF( FIRST.EQ.0 ) THEN
FIRST = -1
CALL INTLOG(JP_DEBUG, 'JACOBI: PBOPEN for write',JPQUIET)
IOFFSET = INDEX(FILEDUM,' ')
CALL PBOPEN(IUNIT,FILEDUM(1:IOFFSET-1),'w',IRET)
IF( IRET.NE.0 ) THEN
C
C Try to use present working directory
C
CALL INTLOG(JP_ERROR,
X 'JACOBI: PBOPEN for write failed',JPQUIET)
FILENAME = COEFILE
FILEDUM = COEFILE
IOFFSET = INDEX(FILEDUM,' ')
CALL PBOPEN(IUNIT,FILEDUM(1:IOFFSET-1),'w',IRET)
IF( IRET.NE.0 ) THEN
CALL INTLOG(JP_ERROR,
X 'JACOBI: PBOPEN for write failed',JPQUIET)
JACOBI = .FALSE.
GOTO 999
ENDIF
ENDIF
ENDIF
C
IF( FIRST.LE.0) THEN
C
PKN = W(K*(NM+1) + (N-K+1))
IF (K.EQ.0) GOTO 400
C
C For K > 0, go forward from zero.
C
PK1N = W((K-1)*(NM+1) + (N-(K-1)+1))
C
C Flip sign if necessary.
C
IF (MOD(K,2).NE.0)THEN
PKN = -PKN
ELSE
PK1N = -PK1N
ENDIF
C
C Work using forward recurrence as long as coefficient
C calculated passes checks.
C
LFOR = .TRUE.
C
RNK0 = PKN
RNK1 = (-DBLE(K)*TANB*PKN + (WISQR(K+1)/SINB)*PK1N)/SQNN
C
C Recurrence starts at 2 for M = 0
C
WIR(1) = RNK0
WIR(2) = RNK1
C
DO 330 MM = 1,N-1
WIR(MM+2) = (2.0*WIR(MM+1)*(DBLE(MM)*COSB-DBLE(K))
X - WISQR(MM+1)*WIR(MM)) /WISQR(MM+2)
C
C Apply check to generated coefficient to see if its
C absolute value is greater than 1. If so, have to
C switch to using backwards recurrences.
C
IF (ABS(WIR(MM+2)).GT.1.0)THEN
LFOR = .FALSE.
IEND = MM + 3
GOTO 335
ENDIF
330 CONTINUE
C
C If forward recurrence appears OK so far,
C test last element RNKN by comparing with WIR(N+1).
C
IEND = N + 2
IF (ABSCHK(RNKN,WIR(N+1))) GOTO 345
C
C If test failed, try generating coefficients using
C backwards recurrences.
C
335 CONTINUE
C
C Work backwards from the top.
C Specify N; K is already set from the loop above.
C Stop at M = 1 (NOT 0).
C
RNKN1 = RNKN*SQ2N*(DBLE(N)*COSB-DBLE(K))
WIR(N+1) = RNKN
C
C Check whether difference is within prescribed tolerance.
C
IF (LFOR .AND. ABSCHK(RNKN1,WIR(N))) GO TO 345
WIR(N) = RNKN1
C
C For M = 0:
C
DO 340 MM = N-1,1,-1
S = (2.0*WIR(MM+1)*(DBLE(MM)*COSB-DBLE(K))
X - (WISQR(MM+2)*WIR(MM+2))) / WISQR(MM+1)
C
C Accept these if forward recursion failed before
C reaching this point.
C
IF (MM+1.LT.IEND)THEN
IF (ABSCHK(S,WIR(MM))) GOTO 345
ENDIF
WIR(MM) = S
C
C If absolute value is greater than 1, give up gracefully
C
IF (ABS(S).GT.1.0) GOTO 920
340 CONTINUE
C
GOTO 920
C
345 CONTINUE
C
C Now RNKM for M = 0,-N
C
C RNKM M = -1,-N
C
C Forward recurrence starts at 1 for M = 0, 2 for -1 etc.
C
LFOR = .TRUE.
C
WIB(1) = RNK0
WIB(2) = -RNK1-RNK0*DBLE(2*K)/(SQNN1)
C
DO 350 MM = 1,(N-1)
WIB(MM+2) = (2.0*WIB(MM+1)*(DBLE(-MM)*COSB-DBLE(K))
X - WISQR(MM+1)*SINB*WIB(MM)) /WISQR(MM+2)
C
C Apply check to generated coefficient to see if its
C absolute value is greater than 1. If so, have to
C switch to using backwards recurrences.
C
IF (ABS(WIB(MM+2)).GT.1.0)THEN
LFOR = .FALSE.
IEND = MM + 3
GOTO 355
ENDIF
350 CONTINUE
C
C If forward recurrence appears OK so far,
C test last element BNKN by comparing with WIB(N+1).
C
IEND = N + 1
IF (ABSCHK(BNKN,WIB(N+1))) GOTO 400
C
C If test failed, try generating coefficients using backwards
C recurrences.
C
355 CONTINUE
C
C Get R values.
C First RNKN, then next highest RNKN1.
C
RNKN1 = -BNKN*SQ2N*(DBLE(N)*COSB + DBLE(K))
C
C Work backwards from the top.
C Specify N; K is already set from the loop above.
C
C Stop at M = 1 (NOT 0).
C
WIB(N+1) = BNKN
IF (LFOR .AND. ABSCHK(RNKN1,WIB(N))) GOTO 400
WIB(N) = RNKN1
C
DO 360 MM = N-1,1,-1
S = (2.0*WIB(MM+1)*(DBLE(-MM)*COSB-DBLE(K))
X - (WISQR(MM+2)*WIB(MM+2))) / WISQR(MM+1)
C
C Accept backwards generated coefficients if forward
C recursion failed before reaching this point.
C
IF ( (MM.LT.IEND ) .AND. ABSCHK(S,WIB(MM)) ) GOTO 400
WIB(MM) = S
C
C If absolute value is greater than 1, give up.
C
IF (ABS(S).GT.1.0) GOTO 910
C
360 CONTINUE
C
C End of backwards recurrences reached with no agreed
C coefficients, give up.
C
GOTO 910
C
C ------------------------------------------------------------------
C* Section 4. Got RNKM. Now transform spectral data.
C ------------------------------------------------------------------
C
400 CONTINUE
C
C Write coefficients to file
C
CALL PBWRITE(IUNIT,WIR,(N+1)*NPBYTES,IRET)
IF( IRET.NE.((N+1)*NPBYTES) ) THEN
CALL INTLOG(JP_FATAL,'JACOBI: PBWRITE failed.',JPQUIET)
CALL PBCLOSE(IUNIT,IRET)
JACOBI = .FALSE.
GOTO 999
ENDIF
C
CALL PBWRITE(IUNIT,WIB,(N+1)*NPBYTES,IRET)
IF( IRET.NE.((N+1)*NPBYTES) ) THEN
CALL INTLOG(JP_FATAL,'JACOBI: PBWRITE failed.',JPQUIET)
CALL PBCLOSE(IUNIT,IRET)
JACOBI = .FALSE.
GOTO 999
ENDIF
ELSE
C
415 CONTINUE
C
PKN = W(K*(NM+1) + (N-K+1))
PK1N = W((K-1)*(NM+1) + (N-(K-1)+1))
C
C Flip sign if necessary.
C
IF (MOD(K,2).NE.0)THEN
PKN = -PKN
ELSE
PK1N = -PK1N
ENDIF
C
C Read coefficients from file
C
CALL PBREAD(IUNIT,WIR,(N+1)*NPBYTES,IRET)
IF( IRET.NE.((N+1)*NPBYTES) ) THEN
CALL INTLOG(JP_FATAL,'JACOBI: PBREAD failed.',JPQUIET)
CALL PBCLOSE(IUNIT,IRET)
JACOBI = .FALSE.
GOTO 999
ENDIF
C
CALL PBREAD(IUNIT,WIB,(N+1)*NPBYTES,IRET)
IF( IRET.NE.((N+1)*NPBYTES) ) THEN
CALL INTLOG(JP_FATAL,'JACOBI: PBREAD failed.',JPQUIET)
CALL PBCLOSE(IUNIT,IRET)
JACOBI = .FALSE.
GOTO 999
ENDIF
C
ENDIF
C
C Special case when K=0.
C
IF( K.EQ.0) THEN
C
SREAL = DATA(2*(N+1)-1)*PKN
SIMAG = 0.0
DO 420 M = 1,N
NMP1TM = (NM+1)*M
SREAL = SREAL
X + 2.0*DATA(2*(NMP1TM-((M-1)*M)/2+1+N-M)-1)
X * W(NMP1TM+(N-M+1))
420 CONTINUE
C
NDEX = 1+N
WIDAT(NN) = SREAL
WIDAT(NN+1) = SIMAG
NN = NN + 2
C
ELSE
C
SREAL = DATA(2*(N+1)-1)*PKN
SIMAG = 0.0
MINUS1 = -1
DO 440 M = 1,N
SREAL = SREAL +
X DATA(2*((NM+1)*M-((M-1)*M)/2+1+N-M)-1)
X * (WIR(M+1)+WIB(M+1)*MINUS1)
SIMAG = SIMAG -
X DATA(2*((NM+1)*M -((M-1)*M)/2+1+N-M))
X * (-WIR(M+1)+WIB(M+1)*MINUS1)
MINUS1 = -MINUS1
440 CONTINUE
C
NDEX = (NM+1)*K - ((K-1)*K)/2+1+N-K
WIDAT(NN) = SREAL
WIDAT(NN+1) = SIMAG
NN = NN + 2
ENDIF
C
C Update RNKN at both ends of the forward and backward
C recurrences.
C
TEMP = DSQRT(DBLE(N+K)/DBLE(N-K+1))
RNKN = RNKN*TEMP*SINB/(1+COSB)
BNKN = -BNKN*TEMP*(1+COSB)/SINB
490 CONTINUE
C
C End of inner loop.
C
C ------------------------------------------------------------------
C* Section 5. Now place the values of the rotated spectral
C coefficients in DATA.
C ------------------------------------------------------------------
C
500 CONTINUE
C
NN = 1
DO 520 K = N,0,-1
NDEX = (NM+1)*K - ((K-1)*K)/2+1+N-K
DATA(2*NDEX-1) = WIDAT(NN)
DATA(2*NDEX) = WIDAT(NN+1)
NN = NN + 2
C
520 CONTINUE
C
530 CONTINUE
C
C ------------------------------------------------------------------
C* Section 9. Return.
C ------------------------------------------------------------------
C
900 CONTINUE
C
JACOBI = .TRUE.
C
C If coefficients file has just been generated:
C - close it,
C - rename it,
C - re-open for reading
C - unlink it, so it can disappear when closed,
C - leave it open.
C
IF( FIRST.LE.0 ) THEN
FIRST = 1
CALL PBCLOSE(IUNIT,IRET)
IF( IRET.NE.0 ) THEN
CALL INTLOG(JP_ERROR,'JACOBI: PBCLOSE failed.',JPQUIET)
JACOBI = .FALSE.
GOTO 999
ENDIF
C
FILEDUM(IOFFSET:IOFFSET) = CHAR(0)
FILENAME(IOFFSET:IOFFSET) = CHAR(0)
IRET = RENAME(FILEDUM(1:IOFFSET-1),FILENAME(1:IOFFSET-1))
IF( IRET.NE.0 ) THEN
CALL INTLOG(JP_FATAL,'JACOBI: RENAME of file failed',JPQUIET)
JACOBI = .FALSE.
GOTO 999
ENDIF
C
CALL INTLOG(JP_DEBUG, 'JACOBI: PBOPEN for read',JPQUIET)
IOFFSET = INDEX(FILENAME,' ')
CALL PBOPEN(IUNIT,FILENAME(1:IOFFSET-1),'r',IRET)
IF( IRET.NE.0 ) THEN
CALL INTLOG(JP_FATAL,'JACOBI: PBOPEN for read failed',JPQUIET)
JACOBI = .FALSE.
GOTO 999
ENDIF
C
IRET = UNLINK(FILENAME(1:IOFFSET-1))
IF( IRET.NE.0 ) THEN
CALL INTLOG(JP_ERROR,'JACOBI: UNLINK of file failed',JPQUIET)
JACOBI = .FALSE.
GOTO 999
ENDIF
ENDIF
C
999 CONTINUE
RETURN
C
C Failure to converge with M < 0.
C
910 CONTINUE
CALL INTLOG(JP_FATAL,'JACOBI: Failure to converge M < 0', JPQUIET)
JACOBI = .FALSE.
GOTO 999
C
C Failure to converge with M > 0.
C
920 CONTINUE
CALL INTLOG(JP_FATAL,'JACOBI: Failure to converge M > 0', JPQUIET)
JACOBI = .FALSE.
GOTO 999
END
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