!........................................................................
!
! Subroutine : SET_NONLIN(NONLIN, disp_file)
!
! Description: Set initial energy and amplitude offsets for closed orbit 
!              calculation near closed orbit for delta E/E = 0. and for an
!
! Arguments  :   
!   INPUT:  NONLIN    Nonlin_struct: Nonlin
!
!   OUTPUT: NONLIN   Nonlin_struct: nonlin.energy_offset and
!                                  nonlin.x_amplitude, nonlin.y_amplitude
!                                  nonlin.delta_orb       
!
! Mod/Commons:    
!
! Calls      :      
!
! Author     : 
!
! Modified   :     
!             
!........................................................................
!
!
! $Log$
! Revision 1.9  2007/01/30 16:15:14  dcs
! merged with branch_bmad_1.
!
! Revision 1.6  2004/11/08 19:16:29  dlr
! replace n_ele_maxx with n_ele_max
!
! Revision 1.5  2003/07/08 19:27:57  mjf7
!
!
! Modified all subroutines to correctly use allocatable lat elements. n_ele_maxx is no longer global, but a member variable of the lat struct. -mjf
!
! Revision 1.4  2003/06/07 20:44:30  cesrulib
! conform to the lahey f95 standard
!
! Revision 1.2  2003/04/30 17:14:54  cesrulib
! dlr's changes since last import
!
! Revision 1.1.1.1  2002/12/13 19:23:30  cesrulib
! import bmadz
!
!
!........................................................................
!


subroutine set_nonlin(nonlin, disp_file, n_ele_max)

  use bmad


  use nonlin_mod
  use constraints_mod
  implicit none

  type (nonlin_ele_struct) nonlin

  character*(*) disp_file
  integer n_ele_max

  character*72 string

  integer i

  nonlin%energies = 3

 nonlin%energy_offset(1) = -0.006
 nonlin%energy_offset(2) =  0.0
 nonlin%energy_offset(3) =  0.006
 nonlin%n_det_calc = 6

 call allocate_nonlin_ele( nonlin, n_ele_max )

! nonlin.delta_orb(i) are the offsets with respect to the closed orbit
! that are used to compute the jacobian. The i=1,10 sets of
! coordinates are for each of the n_det_calc iterations.
! If only i=1 is specified then the supsequent starting points
! are computed internally in subroutine nonlinear_closed_orbit.
! Note that the actual displacement is
!       co.x.pos+sqrt(delta_orb().x.pos * betax)
!       co.x.vel+sqrt(delta_orb().x.vel / betax)               etc.


  forall (i = 1:10) nonlin%delta_orb(i)%vec = 0

  nonlin%delta_orb(1)%vec(1:2) = 4.0e-8
  nonlin%delta_orb(1)%vec(3:4) = 2.25e-6
  nonlin%delta_orb(1)%vec(5:6) = 2.0e-4

  nonlin%delta_orb(2)%vec(1:2) = 2.25e-4
  nonlin%delta_orb(2)%vec(3:4) = 1.0e-8

  nonlin%delta_orb(3)%vec(1:2) = 2.5e-5
  nonlin%delta_orb(3)%vec(3:4) = 1.44e-6

  nonlin%delta_orb(4)%vec(1:4) = 4.0e-8

  nonlin%delta_orb(5)%vec(1:4) = 2.56e-6
  nonlin%delta_orb(5)%vec(3:4) = 2.5e-10

  nonlin%delta_orb(6)%vec(1:2) = 4.0e-10
  nonlin%delta_orb(6)%vec(3:4) = 4.0e-9


  if(disp_file /= 'DEFAULT')then
    open(unit=11, file=disp_file, status='OLD', action='read')
      do i=1, nonlin%n_det_calc
        read(11,'(a)')string
        read(string,*)nonlin%delta_orb(i)%vec(1),nonlin%delta_orb(i)%vec(2),  &
                  nonlin%delta_orb(i)%vec(3),nonlin%delta_orb(i)%vec(4)
      end do
    close(unit=11)
  endif

  return

  end