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Last change
on this file since 966 was
253,
checked in by (none), 23 years ago
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This commit was manufactured by cvs2svn to create branch
'rel-1-0-patch'.
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Property svn:eol-style set to
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Property svn:executable set to
*
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Property svn:keywords set to
Author Date Id Revision
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File size:
2.5 KB
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| 1 | SUBROUTINE JACOBI(A,N,NP,D,V,NROT) |
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| 2 | PARAMETER (NMAX=400) |
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| 3 | DIMENSION A(NP,NP),D(NP),V(NP,NP),B(NMAX),Z(NMAX) |
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| 4 | IF (n.gt.nmax) THEN |
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| 5 | print*, 'n, nmax=', n, nmax |
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| 6 | print*, 'Surdimensionnement insuffisant dans jacobi' |
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| 7 | CALL abort |
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| 8 | ENDIF |
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| 9 | DO 12 IP=1,N |
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| 10 | DO 11 IQ=1,N |
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| 11 | V(IP,IQ)=0. |
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| 12 | 11 CONTINUE |
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| 13 | V(IP,IP)=1. |
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| 14 | 12 CONTINUE |
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| 15 | DO 13 IP=1,N |
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| 16 | B(IP)=A(IP,IP) |
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| 17 | D(IP)=B(IP) |
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| 18 | Z(IP)=0. |
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| 19 | 13 CONTINUE |
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| 20 | NROT=0 |
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| 21 | DO 24 I=1,50 |
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| 22 | SM=0. |
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| 23 | DO 15 IP=1,N-1 |
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| 24 | DO 14 IQ=IP+1,N |
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| 25 | SM=SM+ABS(A(IP,IQ)) |
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| 26 | 14 CONTINUE |
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| 27 | 15 CONTINUE |
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| 28 | IF(SM.EQ.0.)RETURN |
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| 29 | IF(I.LT.4)THEN |
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| 30 | TRESH=0.2*SM/N**2 |
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| 31 | ELSE |
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| 32 | TRESH=0. |
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| 33 | ENDIF |
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| 34 | DO 22 IP=1,N-1 |
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| 35 | DO 21 IQ=IP+1,N |
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| 36 | G=100.*ABS(A(IP,IQ)) |
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| 37 | IF((I.GT.4).AND.(ABS(D(IP))+G.EQ.ABS(D(IP))) |
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| 38 | * .AND.(ABS(D(IQ))+G.EQ.ABS(D(IQ))))THEN |
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| 39 | A(IP,IQ)=0. |
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| 40 | ELSE IF(ABS(A(IP,IQ)).GT.TRESH)THEN |
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| 41 | H=D(IQ)-D(IP) |
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| 42 | IF(ABS(H)+G.EQ.ABS(H))THEN |
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| 43 | T=A(IP,IQ)/H |
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| 44 | ELSE |
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| 45 | THETA=0.5*H/A(IP,IQ) |
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| 46 | T=1./(ABS(THETA)+SQRT(1.+THETA**2)) |
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| 47 | IF(THETA.LT.0.)T=-T |
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| 48 | ENDIF |
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| 49 | C=1./SQRT(1+T**2) |
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| 50 | S=T*C |
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| 51 | TAU=S/(1.+C) |
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| 52 | H=T*A(IP,IQ) |
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| 53 | Z(IP)=Z(IP)-H |
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| 54 | Z(IQ)=Z(IQ)+H |
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| 55 | D(IP)=D(IP)-H |
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| 56 | D(IQ)=D(IQ)+H |
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| 57 | A(IP,IQ)=0. |
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| 58 | DO 16 J=1,IP-1 |
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| 59 | G=A(J,IP) |
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| 60 | H=A(J,IQ) |
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| 61 | A(J,IP)=G-S*(H+G*TAU) |
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| 62 | A(J,IQ)=H+S*(G-H*TAU) |
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| 63 | 16 CONTINUE |
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| 64 | DO 17 J=IP+1,IQ-1 |
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| 65 | G=A(IP,J) |
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| 66 | H=A(J,IQ) |
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| 67 | A(IP,J)=G-S*(H+G*TAU) |
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| 68 | A(J,IQ)=H+S*(G-H*TAU) |
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| 69 | 17 CONTINUE |
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| 70 | DO 18 J=IQ+1,N |
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| 71 | G=A(IP,J) |
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| 72 | H=A(IQ,J) |
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| 73 | A(IP,J)=G-S*(H+G*TAU) |
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| 74 | A(IQ,J)=H+S*(G-H*TAU) |
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| 75 | 18 CONTINUE |
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| 76 | DO 19 J=1,N |
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| 77 | G=V(J,IP) |
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| 78 | H=V(J,IQ) |
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| 79 | V(J,IP)=G-S*(H+G*TAU) |
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| 80 | V(J,IQ)=H+S*(G-H*TAU) |
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| 81 | 19 CONTINUE |
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| 82 | NROT=NROT+1 |
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| 83 | ENDIF |
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| 84 | 21 CONTINUE |
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| 85 | 22 CONTINUE |
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| 86 | DO 23 IP=1,N |
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| 87 | B(IP)=B(IP)+Z(IP) |
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| 88 | D(IP)=B(IP) |
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| 89 | Z(IP)=0. |
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| 90 | 23 CONTINUE |
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| 91 | 24 CONTINUE |
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| 92 | STOP '50 iterations should never happen' |
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| 93 | RETURN |
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| 94 | END |
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