- 积分
- 123
- 贡献
-
- 精华
- 在线时间
- 小时
- 注册时间
- 2012-8-16
- 最后登录
- 1970-1-1
|
登录后查看更多精彩内容~
您需要 登录 才可以下载或查看,没有帐号?立即注册
x
C==================== *SUB JACOBI*===========================
SUBROUTINE JACOBI(N,A,D,V,EVL,B,Z)
DIMENSION A(N,N),D(N),V(N,N),B(N),Z(N)
LOGICAL EVL
IF(.NOT.EVL) GO TO 10
DO 70 IP=1,N
DO 70 IQ=1,N
IF (IP-IQ) 50,60,50
60 V(IP,IP)=1.0
GO TO 70
50 V(IP,IQ)=0.0
70 CONTINUE
10 DO 80 IP=1,N
D(IP)=A(IP,IP)
B(IP)=D(IP)
80 Z(IP)=0.0
IROT=0
DO 370 I=1,50
SM=0.0
NM1=N-1
DO 100 IP=1,NM1
IPP1=IP-1
DO 100 IQ=IPP1,N
100 SM=SM+ABS(A(IP,IQ))
IF (SM) 110,120,110
110 IF (I-4) 130,140,140
130 TRESH=0.2*SM/(FLOAT(N)*FLOAT(N))
GO TO 150
140 TRESH=0.0
150 DO 160 IP=1,NM1
IPP1=IP+1
DO 160 IQ=IPP1,N
G=100.0*ABS(A(IP,IQ))
IF(I.GT.4.AND.ABS(D(IP))+G.EQ.ABS(D(IP)).AND.ABS(D(IQ))+G.EQ.
*ABS(D(IQ))) GO TO 200
IF(ABS(A(IP,IQ)).LE.TRESH) GO TO 160
H=D(IQ)-D(IP)
IF(ABS(H)+G.EQ.ABS(H)) GO TO 240
THETA=0.5*H/A(IP,IQ)
T=1.0/(ABS(THETA)+SQRT(1.0+THETA*THETA))
IF(THETA.LT.0.0) T=-T
GO TO 250
240 T=A(IP,IQ)/H
250 C=1.0/SQRT(1.0+T*T)
S=T*C
H=T*A(IP,IQ)
Z(IP)=Z(IP)-H
Z(IQ)=Z(IQ)+H
D(IP)=D(IP)-H
D(IQ)=D(IQ)+H
A(IP,IQ)=0.0
IPM1=IP-1
IF (IPM1) 260,260,270
270 DO 280 J=1,IPM1
G=A(J,IP)
H=A(J,IQ)
A(J,IP)=C*G-S*H
280 A(J,IQ)=S*G+C*H
260 IQM1=IQ-1
IF (IQM1-IPP1) 300,290,290
290 DO 310 J=IPP1,IQM1
G=A(IP,J)
H=A(J,IQ)
A(IP,J)=C*G-S*H
310 A(J,IQ)=S*G+C*H
300 IQP1=IQ+1
IF (N-IQP1) 330,320,320
320 DO 340 J=IQP1,N
G=A(IP,J)
H=A(IQ,J)
A(IP,J)=C*G-S*H
340 A(IQ,J)=S*G+C*H
330 IF (.NOT.EVL) GO TO 350
DO 360 J=1,N
G=V(J,IP)
H=V(J,IQ)
V(J,IP)=C*G-S*H
360 V(J,IQ)=S*G+C*H
350 IROT=IROT+1
GO TO 160
200 A(IP,IQ)=0.0
160 CONTINUE
DO 370 IP=1,N
B(IP)=B(IP)+Z(IP)
D(IP)=B(IP)
370 Z(IP)=0.0
120 RETURN
END |
|