* F07PJF Example Program Text * Mark 15 Release. NAG Copyright 1991. * .. Parameters .. INTEGER NIN, NOUT PARAMETER (NIN=5,NOUT=6) INTEGER NMAX PARAMETER (NMAX=8) * .. Local Scalars .. INTEGER I, IFAIL, INFO, J, N CHARACTER UPLO * .. Local Arrays .. DOUBLE PRECISION AP(NMAX*(NMAX+1)/2), WORK(NMAX) INTEGER IPIV(NMAX) * .. External Subroutines .. EXTERNAL DSPTRF, DSPTRI, X04CCF * .. Executable Statements .. WRITE (NOUT,*) 'F07PJF 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,*) ((AP(I+J*(J-1)/2),J=I,N),I=1,N) ELSE IF (UPLO.EQ.'L') THEN READ (NIN,*) ((AP(I+(2*N-J)*(J-1)/2),J=1,I),I=1,N) END IF * * Factorize A * CALL DSPTRF(UPLO,N,AP,IPIV,INFO) * WRITE (NOUT,*) IF (INFO.EQ.0) THEN * * Compute inverse of A * CALL DSPTRI(UPLO,N,AP,IPIV,WORK,INFO) * * Print inverse * IFAIL = 0 * CALL X04CCF(UPLO,'Nonunit',N,AP,'Inverse',IFAIL) * ELSE WRITE (NOUT,*) 'The factor D is singular' END IF END IF * END