Program f08qtfe ! F08QTF Example Program Text ! Mark 24 Release. NAG Copyright 2012. ! .. Use Statements .. Use nag_library, Only: nag_wp, x04dbf, ztrexc ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: nin = 5, nout = 6 ! .. Local Scalars .. Integer :: i, ifail, ifst, ilst, info, ldq, & ldt, n ! .. Local Arrays .. Complex (Kind=nag_wp), Allocatable :: q(:,:), t(:,:) Character (1) :: clabs(1), rlabs(1) ! .. Executable Statements .. Write (nout,*) 'F08QTF Example Program Results' Write (nout,*) Flush (nout) ! Skip heading in data file Read (nin,*) Read (nin,*) n ldq = 1 ldt = n Allocate (q(ldq,1),t(ldt,n)) ! Read T from data file Read (nin,*)(t(i,1:n),i=1,n) ! Read the row indices Read (nin,*) ifst, ilst ! Reorder the Schur factor T ! The NAG name equivalent of ztrexc is f08qtf Call ztrexc('No update',n,t,ldt,q,ldq,ifst,ilst,info) If (info/=0) Then Write (nout,99999) info, ilst Write (nout,*) Flush (nout) End If ! Print reordered Schur form ! ifail: behaviour on error exit ! =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft ifail = 0 Call x04dbf('General',' ',n,n,t,ldt,'Bracketed','F7.4', & 'Reordered Schur form','Integer',rlabs,'Integer',clabs,80,0,ifail) 99999 Format (' Reordering could not be completed. INFO = ',I3,' ILST = ',I5) End Program f08qtfe