Last change
on this file since 5005 was
704,
checked in by Laurent Fairhead, 18 years ago
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Inclusion des modifs de Y. Meurdesoif pour la version V3
LF
|
-
Property svn:eol-style set to
native
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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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Line | |
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1 | ! |
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2 | ! $Header$ |
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3 | ! |
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4 | SUBROUTINE JACOBI(A,N,NP,D,V,NROT) |
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5 | PARAMETER (NMAX=400) |
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6 | DIMENSION A(NP,NP),D(NP),V(NP,NP),B(NMAX),Z(NMAX) |
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7 | IF (n.gt.nmax) THEN |
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8 | print*, 'n, nmax=', n, nmax |
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9 | print*, 'Surdimensionnement insuffisant dans jacobi' |
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10 | CALL abort |
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11 | ENDIF |
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12 | DO 12 IP=1,N |
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13 | DO 11 IQ=1,N |
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14 | V(IP,IQ)=0. |
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15 | 11 CONTINUE |
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16 | V(IP,IP)=1. |
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17 | 12 CONTINUE |
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18 | DO 13 IP=1,N |
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19 | B(IP)=A(IP,IP) |
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20 | D(IP)=B(IP) |
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21 | Z(IP)=0. |
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22 | 13 CONTINUE |
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23 | NROT=0 |
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24 | DO 24 I=1,50 |
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25 | SM=0. |
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26 | DO 15 IP=1,N-1 |
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27 | DO 14 IQ=IP+1,N |
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28 | SM=SM+ABS(A(IP,IQ)) |
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29 | 14 CONTINUE |
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30 | 15 CONTINUE |
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31 | IF(SM.EQ.0.)RETURN |
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32 | IF(I.LT.4)THEN |
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33 | TRESH=0.2*SM/N**2 |
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34 | ELSE |
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35 | TRESH=0. |
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36 | ENDIF |
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37 | DO 22 IP=1,N-1 |
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38 | DO 21 IQ=IP+1,N |
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39 | G=100.*ABS(A(IP,IQ)) |
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40 | IF((I.GT.4).AND.(ABS(D(IP))+G.EQ.ABS(D(IP))) |
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41 | * .AND.(ABS(D(IQ))+G.EQ.ABS(D(IQ))))THEN |
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42 | A(IP,IQ)=0. |
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43 | ELSE IF(ABS(A(IP,IQ)).GT.TRESH)THEN |
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44 | H=D(IQ)-D(IP) |
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45 | IF(ABS(H)+G.EQ.ABS(H))THEN |
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46 | T=A(IP,IQ)/H |
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47 | ELSE |
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48 | THETA=0.5*H/A(IP,IQ) |
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49 | T=1./(ABS(THETA)+SQRT(1.+THETA**2)) |
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50 | IF(THETA.LT.0.)T=-T |
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51 | ENDIF |
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52 | C=1./SQRT(1+T**2) |
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53 | S=T*C |
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54 | TAU=S/(1.+C) |
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55 | H=T*A(IP,IQ) |
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56 | Z(IP)=Z(IP)-H |
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57 | Z(IQ)=Z(IQ)+H |
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58 | D(IP)=D(IP)-H |
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59 | D(IQ)=D(IQ)+H |
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60 | A(IP,IQ)=0. |
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61 | DO 16 J=1,IP-1 |
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62 | G=A(J,IP) |
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63 | H=A(J,IQ) |
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64 | A(J,IP)=G-S*(H+G*TAU) |
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65 | A(J,IQ)=H+S*(G-H*TAU) |
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66 | 16 CONTINUE |
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67 | DO 17 J=IP+1,IQ-1 |
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68 | G=A(IP,J) |
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69 | H=A(J,IQ) |
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70 | A(IP,J)=G-S*(H+G*TAU) |
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71 | A(J,IQ)=H+S*(G-H*TAU) |
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72 | 17 CONTINUE |
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73 | DO 18 J=IQ+1,N |
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74 | G=A(IP,J) |
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75 | H=A(IQ,J) |
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76 | A(IP,J)=G-S*(H+G*TAU) |
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77 | A(IQ,J)=H+S*(G-H*TAU) |
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78 | 18 CONTINUE |
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79 | DO 19 J=1,N |
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80 | G=V(J,IP) |
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81 | H=V(J,IQ) |
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82 | V(J,IP)=G-S*(H+G*TAU) |
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83 | V(J,IQ)=H+S*(G-H*TAU) |
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84 | 19 CONTINUE |
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85 | NROT=NROT+1 |
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86 | ENDIF |
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87 | 21 CONTINUE |
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88 | 22 CONTINUE |
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89 | DO 23 IP=1,N |
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90 | B(IP)=B(IP)+Z(IP) |
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91 | D(IP)=B(IP) |
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92 | Z(IP)=0. |
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93 | 23 CONTINUE |
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94 | 24 CONTINUE |
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95 | STOP '50 iterations should never happen' |
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96 | RETURN |
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97 | END |
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