```    Program f08qyfe

!     F08QYF Example Program Text

!     Mark 27.1 Release. NAG Copyright 2020.

!     .. Use Statements ..
Use nag_library, Only: f06uaf, nag_wp, x02ajf, ztrevc, ztrsna
!     .. Implicit None Statement ..
Implicit None
!     .. Parameters ..
Integer, Parameter               :: nin = 5, nout = 6
!     .. Local Scalars ..
Real (Kind=nag_wp)               :: eps, tnorm
Integer                          :: i, info, ldt, ldvl, ldvr, ldwork, m, &
n
!     .. Local Arrays ..
Complex (Kind=nag_wp), Allocatable :: t(:,:), vl(:,:), vr(:,:),          &
work(:,:)
Real (Kind=nag_wp), Allocatable  :: rwork(:), s(:), sep(:)
Logical                          :: select(1)
!     .. Executable Statements ..
Write (nout,*) 'F08QYF Example Program Results'
Write (nout,*)
!     Skip heading in data file
ldt = n
ldvl = n
ldvr = n
ldwork = n
Allocate (t(ldt,n),vl(ldvl,n),vr(ldvr,n),work(ldwork,n+1),rwork(n),s(n), &
sep(n))

!     Read T from data file

!     Calculate the left and right eigenvectors of T

!     The NAG name equivalent of ztrevc is f08qxf
Call ztrevc('Both','All',select,n,t,ldt,vl,ldvl,vr,ldvr,n,m,work,rwork,  &
info)

!     Estimate condition numbers for all the eigenvalues and right
!     eigenvectors of T

!     The NAG name equivalent of ztrsna is f08qyf
Call ztrsna('Both','All',select,n,t,ldt,vl,ldvl,vr,ldvr,s,sep,n,m,work,  &
ldwork,rwork,info)

!     Print condition numbers of eigenvalues and right eigenvectors

Write (nout,*) 'S'
Write (nout,99999) s(1:m)
Write (nout,*)
Write (nout,*) 'SEP'
Write (nout,99999) sep(1:m)

!     Calculate approximate error estimates (using the 1-norm)

eps = x02ajf()
tnorm = f06uaf('1-norm',n,n,t,ldt,rwork)
Write (nout,*)
Write (nout,*) 'Approximate error estimates for eigenvalues ',           &
'of T (machine-dependent)'
Write (nout,99999)(eps*tnorm/s(i),i=1,m)
Write (nout,*)
Write (nout,*) 'Approximate error estimates for right ',                 &
'eigenvectors of T (machine-dependent)'
Write (nout,99999)(eps*tnorm/sep(i),i=1,m)

99999 Format ((3X,1P,7E11.1))
End Program f08qyfe
```