```    Program f08ftfe

!     F08FTF Example Program Text

!     Mark 26.2 Release. NAG Copyright 2017.

!     .. Use Statements ..
Use nag_library, Only: f06tff, nag_wp, x04dbf, zhetrd, zscal, zsteqr,    &
zungtr
!     .. Implicit None Statement ..
Implicit None
!     .. Parameters ..
Integer, Parameter               :: nin = 5, nout = 6
!     .. Local Scalars ..
Integer                          :: i, ifail, info, k, lda, ldz, lwork,  &
n
Character (1)                    :: uplo
!     .. Local Arrays ..
Complex (Kind=nag_wp), Allocatable :: a(:,:), tau(:), work(:), z(:,:)
Real (Kind=nag_wp), Allocatable  :: d(:), e(:), rwork(:)
Character (1)                    :: clabs(1), rlabs(1)
!     .. Intrinsic Procedures ..
Intrinsic                        :: abs, cmplx, conjg, maxloc
!     .. Executable Statements ..
Write (nout,*) 'F08FTF Example Program Results'
!     Skip heading in data file
lda = n
ldz = n
lwork = 64*n
Allocate (a(lda,n),tau(n),work(lwork),z(ldz,n),d(n),e(n),rwork(2*n-2))

!     Read A from data file

If (uplo=='U') Then
Else If (uplo=='L') Then
End If

!     Reduce A to tridiagonal form T = (Q**H)*A*Q

!     The NAG name equivalent of zhetrd is f08fsf
Call zhetrd(uplo,n,a,lda,d,e,tau,work,lwork,info)

!     Copy A into Z
Call f06tff(uplo,n,n,a,lda,z,ldz)

!     Form Q explicitly, storing the result in Z
!     The NAG name equivalent of zungtr is f08ftf
Call zungtr(uplo,n,z,ldz,tau,work,lwork,info)

!     Calculate all the eigenvalues and eigenvectors of A
!     The NAG name equivalent of zsteqr is f08jsf
Call zsteqr('V',n,d,e,z,ldz,rwork,info)

Write (nout,*)
If (info>0) Then
Write (nout,*) 'Failure to converge.'
Else

!       Print eigenvalues and eigenvectors

Write (nout,*) 'Eigenvalues'
Write (nout,99999) d(1:n)
Write (nout,*)
Flush (nout)

!       Normalize the eigenvectors so that the element of largest absolute
!       value is real.
Do i = 1, n
rwork(1:n) = abs(z(1:n,i))
k = maxloc(rwork(1:n),1)
Call zscal(n,conjg(z(k,i))/cmplx(abs(z(k,i)),kind=nag_wp),z(1,i),1)
End Do

!       ifail: behaviour on error exit
!              =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft
ifail = 0
Call x04dbf('General',' ',n,n,z,ldz,'Bracketed','F7.4','Eigenvectors', &
'Integer',rlabs,'Integer',clabs,80,0,ifail)

End If

99999 Format (8X,4(F7.4,11X,:))
End Program f08ftfe
```