File EIGVEC.FC (FOCAL source file)

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LT()BTC U/W-FOCAL:EIGVEC15.10.78?MB3BJC THIS ROUTINE COMPUTES THE EIGENVECTORS OF A(I,J) USING?MCRBTC THE METHOD OF INVERSE ITERATION. GOOD ESTIMATES OF THE?MC1B^C EIGENVALUES ARE REQUIRED FOR RAPID CONVERGENCE AND IM-?MDPB(C PROVED VALUES ARE RETURNED.  
HE FINAL XFORM IS: A*C*B?MDSB2?MD2B<F N=1,!;D 2,3,4,5;CALL THIS SEQUENCE FOR EACH EIGENVALUE?MEQCFF I=1,!;F J=1,!;S A(I,J)=B(I,J);N;N;D 3;RETURN;BOTH SETS?ME*DJCOPY THE MATRIX AND SUBTRACT THE EIGENVALUE?M?E=DTF I=1,!;F J=1,!;S A(I,J)=C(I,J)?M?FRD^F I=1,!
S P(I)=1,A(I,I)=A(I,I)-X(N)?M?F,FJF I=1,!;D -.5;S P(I)=; F J=1,!;I (I-J).4,,.4?M?GNFTF J=!-1,-1,1;S =P(J);F I=1,!;S A(I,J)=A(I,)+.*A(I,)=A(I,J)?M?G0F^R; MATIX INVERSION OF A(I,J) USING THE ROW INTERCHANGE METHOD?M?HMF(S $=A(J,I);Z A(J,I);F K=1,!;S A(J,K)=
(J,K)-A(I,K)*$?MH,F2Z ";F J=I,!;S K=FABS(A(J,I));I (K-").3;S $=A(=J,I),"=K?M?IMF<I ($),.*$=%;F K=A(,I)=1,!;S A(I,K)=A(,K)/$+.*A(,K)=A(I,K)?MI	HJC THIS ROUTINE PERFORMS THE INVERSE ITERATION?M?JAHTF I=1,!;Z Q(I);F J=1,!;S Q(I)=Q(I)+A(I,J)*P(J)?MJ[H^Z $;F I
1,!;I (FABS(Q(I))-FABS($)).1; S $=Q(I)?MJ2H(Z ;F I=1,!;S =+FABS(P(I)-P(I)=Q(I)/$)?MKIH2I (!*%-).2;RETURN; WHEN THINGS CONVERGE?MKJJCORRECT THE EIGENVALUE & NORMALIZE THE VECTOR?M?K:JTS X(N)=X(N)+1/$;Z $;F I=1,!;S $=$+P(I)^2?MJ^S $=FSQT($);F I=1,!;S B(I,N)
P(I)/$;C SAVE IT?M?T?L D EIGVEC;L S EIGVEC;E?M?T C(I)=-	?,I=I-FSGN(I);IF (C).2;GO .2+FOUT(92);RUBOUTS?M?F(IF (C(I)+	:),.*C(I)=-	?;GO .2; REPLACE A 	:	 WITH A NULL?M?L?L D HEADER;L S HEADER;E?M?()-	0)*2^(5-J)?M?ML C LTRHED?M?MO C?M?

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