!------------------------------------------------------------------------
!------------------------------------------------------------------------
!------------------------------------------------------------------------

subroutine get_twiss (ix_ele, ring, twiss_x, twiss_y)

  use cesrv_struct
  use cesrv_interface

  implicit none

  type (lat_struct) ring
  integer ix_ele, ix1, ix2
  type (twiss_struct) :: twiss_x, twiss_y

!

  if (ix_ele == 0) then
    twiss_x%phi = 0
    twiss_y%phi = 0
    twiss_x%beta = 0
    twiss_y%beta = 0
  else
    if (ix_ele > ring%n_ele_track) then
      ix1 = ring%control(ring%ele(ix_ele)%ix1_slave)%slave%ix_ele - 1
      ix2 = ring%control(ring%ele(ix_ele)%ix2_slave)%slave%ix_ele
    else
      ix1 = ix_ele - 1
      ix2 = ix_ele
    endif
    twiss_x%phi = (ring%ele(ix1)%a%phi + ring%ele(ix2)%a%phi) / 2
    twiss_y%phi = (ring%ele(ix1)%b%phi + ring%ele(ix2)%b%phi) / 2
    twiss_x%beta = (ring%ele(ix1)%a%beta + ring%ele(ix2)%a%beta) / 2
    twiss_y%beta = (ring%ele(ix1)%b%beta + ring%ele(ix2)%b%beta) / 2
  endif

end subroutine