program svd_test

! Track n turns
! write matrix x(n,i) where n is turns and i is detector 1:100
! Then do svd and check singular values

   use bmad
   use nr
 
     implicit none

      type (lat_struct) lat
      type (ele_struct) ele 
      type (coord_struct), allocatable :: orbit(:)
      type (coord_struct) start, end

       integer unit, number, m, n_turns/100/, i, ix, nargs

       character*19 file_name
       character*3 num

      character*140 lat_file
      character*120 line, last_line
      character*7 det_name
      character*3 bpm_name

      real(rp) matrix(100,100)

      nargs = cesr_iargc()
      if(nargs == 1)then
         call cesr_getarg(1,lat_file)
         print *, 'Using ', trim(lat_file)
       else
      lat_file = 'bmad.'
      type '(a,$)',' Lattice file name ? (default= bmad.) '
      read(5,'(a)') line
       call string_trim(line, line, ix)
       lat_file = line
       if(ix == 0) lat_file = 'bmad.'
       type *, ' lat_file = ', lat_file
      endif

       call bmad_parser (lat_file, lat)



       call reallocate_coord(orbit,lat%n_ele_max)
       call twiss_at_start(lat)
       call twiss_propagate_all(lat)

       lat%z%tune = 0.05*twopi
       call set_z_tune(lat)
       call calc_z_tune(lat)

      start%vec =0
      start%vec(1) = 0.001
      start%vec(3) = 0.001
      start%vec(6) = 0.001
      do i =1,n_turns

       do m = 1, lat%n_ele_track

        call track1(start, lat%ele(m), lat%param, end)
        if(index(lat%ele(m)%name,'DET_')/= 0)then
         
         num = lat%ele(m)%name(5:7)
         if(num(3:3) /= 'W' .and. num(3:3)/= 'E')cycle
         if(num(1:1) == '0')read(num(2:2),'(i1)')number
         if(num(1:1) /= '0')read(num(1:2),'(i2)')number
         if(num(3:3) == 'E')number = 99-number

        if(i == 1)print '(i,1x,2a,i,1x,f10.4)',m,lat%ele(m)%name, num, number,end%vec(1)
         matrix(i,number) = end%vec(1)
        endif
        start=end
       enddo
     end do
   do m = 1, 99


    write(11, '(20e12.4)')matrix(1:20,m)

  end do
end