Program f07aufe ! F07AUF Example Program Text ! Mark 24 Release. NAG Copyright 2012. ! .. Use Statements .. Use nag_library, Only: nag_wp, x02ajf, zgecon, zgetrf, zlange => f06uaf ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: nin = 5, nout = 6 Character (1), Parameter :: norm = '1' ! .. Local Scalars .. Real (Kind=nag_wp) :: anorm, rcond Integer :: i, info, lda, n ! .. Local Arrays .. Complex (Kind=nag_wp), Allocatable :: a(:,:), work(:) Real (Kind=nag_wp), Allocatable :: rwork(:) Integer, Allocatable :: ipiv(:) ! .. Executable Statements .. Write (nout,*) 'F07AUF Example Program Results' ! Skip heading in data file Read (nin,*) Read (nin,*) n lda = n Allocate (a(lda,n),work(2*n),rwork(2*n),ipiv(n)) ! Read A from data file Read (nin,*)(a(i,1:n),i=1,n) ! Compute norm of A ! f06uaf is the NAG name equivalent of the LAPACK auxiliary zlange anorm = zlange(norm,n,n,a,lda,rwork) ! Factorize A ! The NAG name equivalent of zgetrf is f07arf Call zgetrf(n,n,a,lda,ipiv,info) Write (nout,*) If (info==0) Then ! Estimate condition number ! The NAG name equivalent of zgecon is f07auf Call zgecon(norm,n,a,lda,anorm,rcond,work,rwork,info) If (rcond>=x02ajf()) Then Write (nout,99999) 'Estimate of condition number =', & 1.0_nag_wp/rcond Else Write (nout,*) 'A is singular to working precision' End If Else Write (nout,*) 'The factor U is singular' End If 99999 Format (1X,A,1P,E10.2) End Program f07aufe