```    Program f08nafe

!     F08NAF Example Program Text
!     Mark 26 Release. NAG Copyright 2016.

!     .. Use Statements ..
Use nag_library, Only: dgeev, nag_wp
!     .. Implicit None Statement ..
Implicit None
!     .. Parameters ..
Real (Kind=nag_wp), Parameter    :: zero = 0.0_nag_wp
Integer, Parameter               :: nb = 64, nin = 5, nout = 6
!     .. Local Scalars ..
Complex (Kind=nag_wp)            :: eig
Real (Kind=nag_wp)               :: alpha, beta, scale
Integer                          :: i, info, j, k, lda, ldvr, lwork, n
!     .. Local Arrays ..
Real (Kind=nag_wp), Allocatable  :: a(:,:), vr(:,:), wi(:), work(:),     &
wr(:)
Real (Kind=nag_wp)               :: dummy(1,1)
!     .. Intrinsic Procedures ..
Intrinsic                        :: cmplx, max, maxloc, nint, sqrt
!     .. Executable Statements ..
Write (nout,*) 'F08NAF Example Program Results'
!     Skip heading in data file
lda = n
ldvr = n
Allocate (a(lda,n),vr(ldvr,n),wi(n),wr(n))

!     Use routine workspace query to get optimal workspace.
lwork = -1
!     The NAG name equivalent of dgeev is f08naf
Call dgeev('No left vectors','Vectors (right)',n,a,lda,wr,wi,dummy,1,vr, &
ldvr,dummy,lwork,info)

!     Make sure that there is enough workspace for block size nb.
lwork = max((nb+2)*n,nint(dummy(1,1)))
Allocate (work(lwork))

!     Read the matrix A from data file

!     Compute the eigenvalues and right eigenvectors of A

!     The NAG name equivalent of dgeev is f08naf
Call dgeev('No left vectors','Vectors (right)',n,a,lda,wr,wi,dummy,1,vr, &
ldvr,work,lwork,info)

If (info==0) Then

!       Print solution

Do j = 1, n
Write (nout,*)
If (wi(j)==zero) Then
Write (nout,99999) 'Eigenvalue(', j, ') = ', wr(j)
Else
eig = cmplx(wr(j),wi(j),kind=nag_wp)
Write (nout,99998) 'Eigenvalue(', j, ') = ', eig
End If
Write (nout,*)
Write (nout,99997) 'Eigenvector(', j, ')'
If (wi(j)==zero) Then
!           Scale by making largest element positive
k = maxloc(vr(1:n,j),1)
If (vr(k,j)<zero) Then
vr(1:n,j) = -vr(1:n,j)
End If
Write (nout,99996) vr(1:n,j)
Else If (wi(j)>0.0E0_nag_wp) Then
!           Scale by making largest element real and positive
work(1:n) = vr(1:n,j)**2 + vr(1:n,j+1)**2
k = maxloc(work(1:n),1)
scale = sqrt(work(k))
work(1:n) = vr(1:n,j)
alpha = vr(k,j)/scale
beta = vr(k,j+1)/scale
vr(1:n,j) = alpha*work(1:n) + beta*vr(1:n,j+1)
vr(1:n,j+1) = alpha*vr(1:n,j+1) - beta*work(1:n)
Write (nout,99995)(vr(i,j),vr(i,j+1),i=1,n)
Else
Write (nout,99995)(vr(i,j-1),-vr(i,j),i=1,n)
End If
End Do
Else
Write (nout,*)
Write (nout,99994) 'Failure in DGEEV.  INFO = ', info
End If

99999 Format (1X,A,I2,A,1P,E11.4)
99998 Format (1X,A,I2,A,'(',1P,E11.4,',',1P,E11.4,')')
99997 Format (1X,A,I2,A)
99996 Format (1X,1P,E11.4)
99995 Format (1X,'(',1P,E11.4,',',1P,E11.4,')')
99994 Format (1X,A,I4)
End Program f08nafe
```