!Testing the QR_SHIFT subroutine...
!NB: A and n are changed during QR decomposition!

program SHIFT_TEST
implicit none
                                                                                
     integer, parameter :: dbl=SELECTED_REAL_KIND(14), n=3, n_save=3
     real(KIND=dbl), dimension(n,n) :: A, Q, R
     real(KIND=dbl) ::  e(n)
     integer :: i
                                                                                
A(1,1)=1  ; A(1,2)=-2 ; A(1,3)=0
A(2,1)=-2 ; A(2,2)=7  ; A(2,3)=5
A(3,1)=0 ; A(3,2)=5  ; A(3,3)=-3

call MATOUT("A is:", A, n, n)

CALL QR_SHIFT(A, n, e)

call MATOUT("Eigenvalues of A are:", e, n, 1)

end program SHIFT_TEST