Program f07fufe ! F07FUF Example Program Text ! Mark 24 Release. NAG Copyright 2012. ! .. Use Statements .. Use nag_library, Only: nag_wp, x02ajf, zlanhe => f06ucf, zpocon, zpotrf ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: nin = 5, nout = 6 ! .. Local Scalars .. Real (Kind=nag_wp) :: anorm, rcond Integer :: i, info, lda, n Character (1) :: uplo ! .. Local Arrays .. Complex (Kind=nag_wp), Allocatable :: a(:,:), work(:) Real (Kind=nag_wp), Allocatable :: rwork(:) ! .. Executable Statements .. Write (nout,*) 'F07FUF Example Program Results' ! Skip heading in data file Read (nin,*) Read (nin,*) n lda = n Allocate (a(lda,n),work(2*n),rwork(n)) ! Read A from data file Read (nin,*) uplo 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 ! Compute norm of A ! f06ucf is the NAG name equivalent of the LAPACK auxiliary zlanhe anorm = zlanhe('1-norm',uplo,n,a,lda,rwork) ! Factorize A ! The NAG name equivalent of zpotrf is f07frf Call zpotrf(uplo,n,a,lda,info) Write (nout,*) If (info==0) Then ! Estimate condition number ! The NAG name equivalent of zpocon is f07fuf Call zpocon(uplo,n,a,lda,anorm,rcond,work,rwork,info) If (rcond>=x02ajf()) Then Write (nout,99999) 'Estimate of condition number =', & 1.0E0_nag_wp/rcond Else Write (nout,*) 'A is singular to working precision' End If Else Write (nout,*) 'A is not positive definite' End If 99999 Format (1X,A,1P,E10.2) End Program f07fufe