* F04AHF Example Program Text * Mark 14 Revised. NAG Copyright 1989. * .. Parameters .. INTEGER NMAX, IR, IAA, IA, IB, IX, IBB PARAMETER (NMAX=8,IR=1,IAA=NMAX,IA=NMAX,IB=NMAX,IX=NMAX, + IBB=NMAX) INTEGER NIN, NOUT PARAMETER (NIN=5,NOUT=6) * .. Local Scalars .. DOUBLE PRECISION D1, EPS INTEGER I, ID, IFAIL, J, K, N * .. Local Arrays .. DOUBLE PRECISION A(IA,NMAX), AA(IAA,NMAX), B(IB,IR), BB(IBB,IR), + P(NMAX), X(IX,IR) * .. External Functions .. DOUBLE PRECISION X02AJF EXTERNAL X02AJF * .. External Subroutines .. EXTERNAL F03AFF, F04AHF * .. Executable Statements .. WRITE (NOUT,*) 'F04AHF Example Program Results' * Skip heading in data file READ (NIN,*) READ (NIN,*) N WRITE (NOUT,*) IF (N.GT.0 .AND. N.LE.NMAX) THEN READ (NIN,*) ((AA(I,J),J=1,N),I=1,N) DO 40 I = 1, N DO 20 J = 1, N A(J,I) = AA(J,I) 20 CONTINUE 40 CONTINUE EPS = X02AJF() IFAIL = 1 * * Crout decomposition CALL F03AFF(N,EPS,AA,IAA,D1,ID,P,IFAIL) * IF (IFAIL.NE.0) THEN WRITE (NOUT,99998) 'Error in F03AFF. IFAIL =', IFAIL ELSE READ (NIN,*) ((B(I,J),J=1,IR),I=1,N) IFAIL = 1 * * Accurate solution of linear equations CALL F04AHF(N,IR,A,IA,AA,IAA,P,B,IB,EPS,X,IX,BB,IBB,K,IFAIL) * IF (IFAIL.NE.0) THEN WRITE (NOUT,99998) 'Error in F04AHF. IFAIL =', IFAIL ELSE WRITE (NOUT,*) ' Solution' DO 60 I = 1, N WRITE (NOUT,99999) (X(I,J),J=1,IR) 60 CONTINUE END IF END IF ELSE WRITE (NOUT,99998) 'N is out of range: N = ', N END IF STOP * 99999 FORMAT (1X,8F9.4) 99998 FORMAT (1X,A,I5) END