* F07TUF Example Program Text * Mark 16 Release. NAG Copyright 1993. * .. Parameters .. INTEGER NIN, NOUT PARAMETER (NIN=5,NOUT=6) INTEGER NMAX, LDA PARAMETER (NMAX=8,LDA=NMAX) CHARACTER NORM, DIAG PARAMETER (NORM='1',DIAG='N') * .. Local Scalars .. DOUBLE PRECISION RCOND INTEGER I, INFO, J, N CHARACTER UPLO * .. Local Arrays .. COMPLEX *16 A(LDA,NMAX), WORK(2*NMAX) DOUBLE PRECISION RWORK(NMAX) * .. External Functions .. DOUBLE PRECISION X02AJF EXTERNAL X02AJF * .. External Subroutines .. EXTERNAL ZTRCON * .. Executable Statements .. WRITE (NOUT,*) 'F07TUF Example Program Results' * Skip heading in data file READ (NIN,*) READ (NIN,*) N IF (N.LE.NMAX) THEN * * Read A from data file * READ (NIN,*) UPLO IF (UPLO.EQ.'U') THEN READ (NIN,*) ((A(I,J),J=I,N),I=1,N) ELSE IF (UPLO.EQ.'L') THEN READ (NIN,*) ((A(I,J),J=1,I),I=1,N) END IF * * Estimate condition number * CALL ZTRCON(NORM,UPLO,DIAG,N,A,LDA,RCOND,WORK,RWORK,INFO) * WRITE (NOUT,*) IF (RCOND.GE.X02AJF()) THEN WRITE (NOUT,99999) 'Estimate of condition number =', + 1.0D0/RCOND ELSE WRITE (NOUT,*) 'A is singular to working precision' END IF END IF * 99999 FORMAT (1X,A,1P,E10.2) END