* F07FEF Example Program Text * Mark 15 Release. NAG Copyright 1991. * .. Parameters .. INTEGER NIN, NOUT PARAMETER (NIN=5,NOUT=6) INTEGER NMAX, LDA, NRHMAX, LDB PARAMETER (NMAX=8,LDA=NMAX,NRHMAX=NMAX,LDB=NMAX) * .. Local Scalars .. INTEGER I, IFAIL, INFO, J, N, NRHS CHARACTER UPLO * .. Local Arrays .. DOUBLE PRECISION A(LDA,NMAX), B(LDB,NRHMAX) * .. External Subroutines .. EXTERNAL DPOTRF, DPOTRS, X04CAF * .. Executable Statements .. WRITE (NOUT,*) 'F07FEF Example Program Results' * Skip heading in data file READ (NIN,*) READ (NIN,*) N, NRHS IF (N.LE.NMAX .AND. NRHS.LE.NRHMAX) THEN * * Read A and B 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 READ (NIN,*) ((B(I,J),J=1,NRHS),I=1,N) * * Factorize A * CALL DPOTRF(UPLO,N,A,LDA,INFO) * WRITE (NOUT,*) IF (INFO.EQ.0) THEN * * Compute solution * CALL DPOTRS(UPLO,N,NRHS,A,LDA,B,LDB,INFO) * * Print solution * IFAIL = 0 CALL X04CAF('General',' ',N,NRHS,B,LDB,'Solution(s)',IFAIL) ELSE WRITE (NOUT,*) 'A is not positive-definite' END IF END IF STOP * END