* F11JSF Example Program Text * Mark 19 Release. NAG Copyright 1999. * .. Parameters .. INTEGER NIN, NOUT PARAMETER (NIN=5,NOUT=6) INTEGER NMAX, LA, LWORK PARAMETER (NMAX=1000,LA=10000,LWORK=7*NMAX+120) * .. Local Scalars .. DOUBLE PRECISION OMEGA, RNORM, TOL INTEGER I, IFAIL, ITN, MAXITN, N, NNZ CHARACTER PRECON CHARACTER*6 METHOD * .. Local Arrays .. COMPLEX *16 A(LA), B(NMAX), WORK(LWORK), X(NMAX) DOUBLE PRECISION RDIAG(NMAX) INTEGER ICOL(LA), IROW(LA), IWORK(NMAX+1) * .. External Subroutines .. EXTERNAL F11JSF * .. Executable Statements .. WRITE (NOUT,*) 'F11JSF Example Program Results' * Skip heading in data file READ (NIN,*) * * Read algorithmic parameters * READ (NIN,*) N IF (N.LE.NMAX) THEN READ (NIN,*) NNZ READ (NIN,*) METHOD, PRECON READ (NIN,*) OMEGA READ (NIN,*) TOL, MAXITN * * Read the matrix A * DO 20 I = 1, NNZ READ (NIN,*) A(I), IROW(I), ICOL(I) 20 CONTINUE * * Read rhs vector b and initial approximate solution x * READ (NIN,*) (B(I),I=1,N) READ (NIN,*) (X(I),I=1,N) * * Solve Ax = b using F11JSF * IFAIL = 0 CALL F11JSF(METHOD,PRECON,N,NNZ,A,IROW,ICOL,OMEGA,B,TOL,MAXITN, + X,RNORM,ITN,RDIAG,WORK,LWORK,IWORK,IFAIL) * WRITE (NOUT,99999) 'Converged in', ITN, ' iterations' WRITE (NOUT,99998) 'Final residual norm =', RNORM * * Output x * DO 40 I = 1, N WRITE (NOUT,99997) X(I) 40 CONTINUE END IF STOP * 99999 FORMAT (1X,A,I10,A) 99998 FORMAT (1X,A,1P,E16.3) 99997 FORMAT (1X,'(',E16.4,',',E16.4,')') END