CLS
C = 0
PRINT "EIGENVALUES OF A GENERAL MATRIX"
PRINT
DIM A(20,20):DIM L(20,20):DIM U(20,20)
INPUT "KEY IN ORDER OF MATRIX ";N
PRINT
PRINT "INPUT ELEMENTS OF MATRIX A"
PRINT
FOR I=1 TO N
FOR J = 1 TO N
PRINT "A("; I;", ";J;") =";
INPUT AAA
A(I,J)=AAA
NEXT J: PRINT: NEXT I
M = 0
FOR I = 1 TO N: FOR J= 1 TO N
L(I,J) = 0:U(I,J) = 0
NEXT J: NEXT I
FOR K = 1 TO N
L(K,K)=1:U(K,K)= 1
NEXT K
PRINT
PRINT "RUNNING"
[TWZEZE]
FOR H= 1 TO N
U(1,H) = A(1,H)
NEXT H
FOR H = 2 TO N
L(H,1)= A(H,1) / A(1, 1)
U(2,H) = A(2,H) -L(2, 1) * U(1,H)
NEXT H
J = 2
[TWEIZE]
FOR I = J TO N
IF I<= J THEN [THFIZE]
T = 0
FOR K = 1 TO J -1
T = T + L(I,K) * U(K,J)
NEXT K
L(I,J) =(A(I,J)-T)/U(J,J)
[THFIZE]
NEXT I
J = J + 1
IF J > N THEN [FOSIZE]
FOR I = J TO N
T = 0
FOR K = 1 TO J-1
T = T + L(J,K) * U(K,I)
NEXT K
U(J,I) = A(J,I)-T
NEXT I
GOTO [TWEIZE]
[FOSIZE]
M = M + 1
IF C = 0 THEN A1=U(1,1):C=1:GOTO [FITWZE]
A0= U(1,1):C = 0
[FITWZE]
FOR I = 1 TO N
FOR J = 1 TO N
A(I,J) = 0
FOR K = 1 TO N
A(I,J) = A(I,J) + U(I,K) * L(K,J)
NEXT K: NEXT J: NEXT I
IF A0 <> A1 THEN [TWZEZE]
PRINT "NUMBER OF CYCLES COMPLETED = ";M
PRINT
PRINT"ELEMENTS OF UPPER TRIANGULAR MATRIX"
PRINT
FOR I = 1 TO N
PRINT "";U(I,I)
NEXT I
END