PROGRAM f07kdfe ! F07KDF Example Program Text ! Mark 23 Release. NAG Copyright 2011. ! .. Use Statements .. USE nag_library, ONLY : dpstrf, nag_wp, x04caf, x04ebf ! .. Implicit None Statement .. IMPLICIT NONE ! .. Parameters .. REAL (KIND=nag_wp), PARAMETER :: zero = 0.0E0_nag_wp INTEGER, PARAMETER :: nin = 5, nout = 6 ! .. Local Scalars .. REAL (KIND=nag_wp) :: tol INTEGER :: i, ifail, info, j, lda, n, rank CHARACTER (1) :: uplo ! .. Local Arrays .. REAL (KIND=nag_wp), ALLOCATABLE :: a(:,:), work(:) INTEGER, ALLOCATABLE :: piv(:) CHARACTER (1) :: clabs(1), rlabs(1) ! .. Executable Statements .. WRITE (nout,*) 'F07KDF Example Program Results' ! Skip heading in data file READ (nin,*) READ (nin,*) n, uplo lda = n ALLOCATE (a(lda,n),piv(n),work(2*n)) ! Read A from data file IF (uplo=='U') THEN READ (nin,*) (a(i,i:n),i=1,n) ELSE IF (uplo=='L') THEN READ (nin,*) (a(i,1:i),i=1,n) END IF tol = -1.0_nag_wp ! Factorize A info = 0 ! The NAG name equivalent of dpstrf is f07kdf CALL dpstrf(uplo,n,a,lda,piv,rank,tol,work,info) ! Zero out columns rank+1 to n IF (uplo=='U') THEN DO j = rank + 1, n a(rank+1:j,j) = zero END DO ELSE IF (uplo=='L') THEN DO j = rank + 1, n a(j:n,j) = zero END DO END IF ! Print rank WRITE (nout,*) WRITE (nout,'(1X,A15,I3)') 'Computed rank: ', rank ! Print factor WRITE (nout,*) FLUSH (nout) ifail = 0 CALL x04caf(uplo,'Nonunit',n,n,a,lda,'Factor',ifail) ! Print pivot indices WRITE (nout,*) WRITE (nout,*) 'PIV' FLUSH (nout) ifail = 0 CALL x04ebf('General','Non-unit',1,n,piv,1,'I11',' ','No',rlabs,'No', & clabs,80,1,ifail) END PROGRAM f07kdfe