* F07FJF Example Program Text * Mark 15 Release. NAG Copyright 1991. * .. Parameters .. INTEGER NIN, NOUT PARAMETER (NIN=5,NOUT=6) INTEGER NMAX, LDA PARAMETER (NMAX=8,LDA=NMAX) * .. Local Scalars .. INTEGER I, IFAIL, INFO, J, N CHARACTER UPLO * .. Local Arrays .. DOUBLE PRECISION A(LDA,NMAX) * .. External Subroutines .. EXTERNAL DPOTRF, DPOTRI, X04CAF * .. Executable Statements .. WRITE (NOUT,*) 'F07FJF 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 * * Factorize A * CALL DPOTRF(UPLO,N,A,LDA,INFO) * WRITE (NOUT,*) IF (INFO.EQ.0) THEN * * Compute inverse of A * CALL DPOTRI(UPLO,N,A,LDA,INFO) * * Print inverse * IFAIL = 0 CALL X04CAF(UPLO,'Nonunit',N,N,A,LDA,'Inverse',IFAIL) ELSE WRITE (NOUT,*) 'A is not positive-definite' END IF END IF STOP * END