File: MATINV.FC of Tape: Various/ETH/fc1

(.FC,.FO Focal format converted to 'WRITE' listing) 

---

C-OS/8 FOCAL, 1972

01.01 C MATRIX-INVERSION AND SOLUTION OF LINEAR EQUATIONS
01.02 T !,"SOLUTION OF AX=B BY INVERSION",!!
01.03 A "SIZE OF MATRIX",L,!!
01.05 T :9,"\"
01.06 F J=1,L;T %1,:11*J,"A(J,",J,")"
01.07 T :11*J-2,"\  B(J)",!
01.08 F K=0,5+11*J;T "-"
01.10 S N=L-1;S I=-1
01.20 F K=0,N;S R(K)=100;S S(K)=100
01.30 F J=0,N;T !,:9,"\",!,"A(",J,",K)\";F K=0,L;A :10+K*10, A(J+L*K)
01.40 S M=1E-6
01.50 F J=0,N;F K=0,N;D 5
01.60 I (M-1E-6)1.7,,1.7
01.70 S R(P)=Q;S S(Q)=P;S M=1/M
01.80 F K=0,N;S A(P+L*K)=-A(P+L*K)*M
01.85 F J=0,N;F K=0,N;D 6
01.90 F J=0,N;S A(J+L*Q)=A(J+L*Q)*M
01.92 S A(P+L*Q)=M
01.95 S I=I+1;I (I-N)1.4,1.96,1.4
01.96 D 2
01.98 R

02.01 T !!!,"INVERTED MATRIX:"
02.02 T !;F J=0,16+11*L;T "-"
02.10 F J=0,N;T !,:9,"\",!,:9,"\";F K=0,N;T :10+11*K,%8.04,A(S(J)+L*R(K))
02.20 F J=0,N;S X(J)=0
02.25 T !!,"SOLUTION:",!;F J=1,10;T "="
02.30 F J=0,N;F K=0,N;S X(J)=X(J)+A(S(J)+L*R(K))*A(K+L*L)
02.40 F J=0,N;T !,%1,"X(",J,")  =",%8.04,X(J)
02.50 A !!,"ANY MORE CONSTANTS B(J)",X,!!
02.60 I (X-0YES)2.9,2.7,2.9
02.70 F J=0,N;T !,"B(",%1,J,")";A A(J+L*L)
02.80 G 2.2
02.90 R

05.10 I (R(J)-50)5.9;
05.20 I (S(K)-50)5.9;
05.40 I (FABS(A(J+L*K))-FABS(M))5.9;
05.50 S M=A(J+L*K)
05.60 S P=J;S Q=K
05.90 R

06.10 I (J-P)6.2,6.9,6.2
06.20 I (K-Q)6.3,6.9,6.3
06.30 S A(J+L*K)=A(J+L*K)+A(P+L*K)*A(J+L*Q)
06.90 R

---