!........................................................................
!
! Subroutine :CUSTOM_closed_orbit(LAT, closed, idim)
!
! Description: If there are wigglers that use custom tracking it is sometimes
!              difficult to find a closed orbit. In this subroutine
!               1.Identify custom wigglers that use integration for tracking
!               2.Set type use linear map for initial closed orbit
!               3.Set type to runge kutta for closed orbit determined
!                with closed_orbit_at_start
!
! Arguments  : Input:
!                  LAT    -- lat_struct: Lat containing the lattice.
!
!              Output:
!                  CLOSED -- Closed orbit coordinates          
!-

subroutine custom_closed_orbit (lat, closed, idim)

  use bmad

  implicit none

  type (lat_struct)  lat
  type (bmad_common_struct)  com_saved
  type (coord_struct), allocatable ::  closed(:)

  integer i, idim
  real(rp) eps_rel(4), eps_abs(4)

  character*12 type(lat%n_ele_max)

!

  com_saved = bmad_com

  do i=1,lat%n_ele_track
    if(lat%ele(i)%key == custom$)type(i) = lat%ele(i)%type
    if(lat%ele(i)%key == custom$)lat%ele(i)%type = 'LINEAR'
  end do
  call twiss_at_start (lat)
  closed(0)%vec(:) = 0.
  call closed_orbit_calc( lat, closed, 4 )
  do i=1,lat%n_ele_track
    if(lat%ele(i)%key == custom$)lat%ele(i)%type = type(i)
  end do
  eps_rel(:) = 0.000001
  eps_abs(:) = 0.000001
  call closed_orbit_from_tracking( lat, closed, 4, eps_rel, eps_abs, closed(0) )

  bmad_com%aperture_limit_on = .true.
  bmad_com = com_saved
end subroutine