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! $Header: /home/cvsroot/LMDZ4/libf/filtrez/jacobi.F,v 1.1.1.1 2004/05/19 12:53:09 lmdzadmin Exp $ |
! $Header: /home/cvsroot/LMDZ4/libf/filtrez/jacobi.F,v 1.1.1.1 2004/05/19 |
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! 12:53:09 lmdzadmin Exp $ |
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SUBROUTINE JACOBI(A,N,NP,D,V,NROT) |
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PARAMETER (NMAX=400) |
SUBROUTINE jacobi(a, n, np, d, v, nrot) |
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DIMENSION A(NP,NP),D(NP),V(NP,NP),B(NMAX),Z(NMAX) |
PARAMETER (nmax=400) |
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IF (n.gt.nmax) THEN |
DIMENSION a(np, np), d(np), v(np, np), b(nmax), z(nmax) |
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print*, 'n, nmax=', n, nmax |
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print*, 'Surdimensionnement insuffisant dans jacobi' |
IF (n>nmax) THEN |
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stop 1 |
PRINT *, 'n, nmax=', n, nmax |
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ENDIF |
PRINT *, 'Surdimensionnement insuffisant dans jacobi' |
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DO 12 IP=1,N |
STOP 1 |
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DO 11 IQ=1,N |
END IF |
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V(IP,IQ)=0. |
DO ip = 1, n |
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11 CONTINUE |
DO iq = 1, n |
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V(IP,IP)=1. |
v(ip, iq) = 0. |
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12 CONTINUE |
END DO |
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DO 13 IP=1,N |
v(ip, ip) = 1. |
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B(IP)=A(IP,IP) |
END DO |
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D(IP)=B(IP) |
DO ip = 1, n |
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Z(IP)=0. |
b(ip) = a(ip, ip) |
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13 CONTINUE |
d(ip) = b(ip) |
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NROT=0 |
z(ip) = 0. |
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DO 24 I=1,50 |
END DO |
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SM=0. |
nrot = 0 |
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DO 15 IP=1,N-1 |
DO i = 1, 50 |
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DO 14 IQ=IP+1,N |
sm = 0. |
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SM=SM+ABS(A(IP,IQ)) |
DO ip = 1, n - 1 |
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14 CONTINUE |
DO iq = ip + 1, n |
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15 CONTINUE |
sm = sm + abs(a(ip,iq)) |
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IF(SM.EQ.0.)RETURN |
END DO |
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IF(I.LT.4)THEN |
END DO |
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TRESH=0.2*SM/N**2 |
IF (sm==0.) RETURN |
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ELSE |
IF (i<4) THEN |
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TRESH=0. |
tresh = 0.2*sm/n**2 |
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ENDIF |
ELSE |
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DO 22 IP=1,N-1 |
tresh = 0. |
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DO 21 IQ=IP+1,N |
END IF |
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G=100.*ABS(A(IP,IQ)) |
DO ip = 1, n - 1 |
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IF((I.GT.4).AND.(ABS(D(IP))+G.EQ.ABS(D(IP))) |
DO iq = ip + 1, n |
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* .AND.(ABS(D(IQ))+G.EQ.ABS(D(IQ))))THEN |
g = 100.*abs(a(ip,iq)) |
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A(IP,IQ)=0. |
IF ((i>4) .AND. (abs(d(ip))+g==abs(d(ip))) .AND. (abs(d(iq))+g==abs( & |
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ELSE IF(ABS(A(IP,IQ)).GT.TRESH)THEN |
d(iq)))) THEN |
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H=D(IQ)-D(IP) |
a(ip, iq) = 0. |
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IF(ABS(H)+G.EQ.ABS(H))THEN |
ELSE IF (abs(a(ip,iq))>tresh) THEN |
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T=A(IP,IQ)/H |
h = d(iq) - d(ip) |
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ELSE |
IF (abs(h)+g==abs(h)) THEN |
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THETA=0.5*H/A(IP,IQ) |
t = a(ip, iq)/h |
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T=1./(ABS(THETA)+SQRT(1.+THETA**2)) |
ELSE |
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IF(THETA.LT.0.)T=-T |
theta = 0.5*h/a(ip, iq) |
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ENDIF |
t = 1./(abs(theta)+sqrt(1.+theta**2)) |
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C=1./SQRT(1+T**2) |
IF (theta<0.) t = -t |
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S=T*C |
END IF |
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TAU=S/(1.+C) |
c = 1./sqrt(1+t**2) |
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H=T*A(IP,IQ) |
s = t*c |
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Z(IP)=Z(IP)-H |
tau = s/(1.+c) |
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Z(IQ)=Z(IQ)+H |
h = t*a(ip, iq) |
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D(IP)=D(IP)-H |
z(ip) = z(ip) - h |
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D(IQ)=D(IQ)+H |
z(iq) = z(iq) + h |
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A(IP,IQ)=0. |
d(ip) = d(ip) - h |
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DO 16 J=1,IP-1 |
d(iq) = d(iq) + h |
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G=A(J,IP) |
a(ip, iq) = 0. |
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H=A(J,IQ) |
DO j = 1, ip - 1 |
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A(J,IP)=G-S*(H+G*TAU) |
g = a(j, ip) |
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A(J,IQ)=H+S*(G-H*TAU) |
h = a(j, iq) |
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16 CONTINUE |
a(j, ip) = g - s*(h+g*tau) |
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DO 17 J=IP+1,IQ-1 |
a(j, iq) = h + s*(g-h*tau) |
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G=A(IP,J) |
END DO |
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H=A(J,IQ) |
DO j = ip + 1, iq - 1 |
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A(IP,J)=G-S*(H+G*TAU) |
g = a(ip, j) |
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A(J,IQ)=H+S*(G-H*TAU) |
h = a(j, iq) |
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17 CONTINUE |
a(ip, j) = g - s*(h+g*tau) |
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DO 18 J=IQ+1,N |
a(j, iq) = h + s*(g-h*tau) |
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G=A(IP,J) |
END DO |
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H=A(IQ,J) |
DO j = iq + 1, n |
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A(IP,J)=G-S*(H+G*TAU) |
g = a(ip, j) |
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A(IQ,J)=H+S*(G-H*TAU) |
h = a(iq, j) |
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18 CONTINUE |
a(ip, j) = g - s*(h+g*tau) |
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DO 19 J=1,N |
a(iq, j) = h + s*(g-h*tau) |
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G=V(J,IP) |
END DO |
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H=V(J,IQ) |
DO j = 1, n |
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V(J,IP)=G-S*(H+G*TAU) |
g = v(j, ip) |
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V(J,IQ)=H+S*(G-H*TAU) |
h = v(j, iq) |
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19 CONTINUE |
v(j, ip) = g - s*(h+g*tau) |
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NROT=NROT+1 |
v(j, iq) = h + s*(g-h*tau) |
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ENDIF |
END DO |
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21 CONTINUE |
nrot = nrot + 1 |
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22 CONTINUE |
END IF |
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DO 23 IP=1,N |
END DO |
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B(IP)=B(IP)+Z(IP) |
END DO |
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D(IP)=B(IP) |
DO ip = 1, n |
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Z(IP)=0. |
b(ip) = b(ip) + z(ip) |
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23 CONTINUE |
d(ip) = b(ip) |
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24 CONTINUE |
z(ip) = 0. |
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STOP '50 iterations should never happen' |
END DO |
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RETURN |
END DO |
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END |
STOP '50 iterations should never happen' |
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RETURN |
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END SUBROUTINE jacobi |