pro export_particles_for_ralf, only_current=ocurrent
@TOOLS/common_blocks.inc
if N_ELEMENTS(*parti.names) eq 0 or (*parti.names)[0] eq '' then return
names = (*parti.names)


  filename = DIALOG_PICKFILE(FILTER="*.mdmp", PATH=data_dir, $
                             FILE=default_filename, DIALOG_PARENT=BASE2, $
                             TITLE="Select ralfs particles mdmp Export Filename", $
                             GET_PATH=data_dir, /NOCONFIRM, /WRITE, $
                             /OVERWRITE_PROMPT)
  if filename eq '' then return
  mdmp_pos = strpos(filename, '.mdmp')
  if mdmp_pos lt 0 then begin
     print, 'export_particles_for_ralf:', filename, ' filename has to end in .mdmp'
     return
  endif

  if N_elements(ocurrent) eq 0 then begin
     ocurrent = 0
     these_grids = all_grid_info 
  endif else these_grids=grid_info

  ind = where(these_grids.num_particle gt 0, count)
  if count gt 0 then these_grids = these_grids[ind] else begin
     print, 'export_particles_for_ralf: no grids with particles found'
     return
  endelse

  h = histogram(these_grids.timestep, reverse_indices=r)
  ntimesteps = N_elements(where(h gt 0)) 

  slashisat = strpos(filename, '/', /reverse_search)

  fbase = strmid(filename, 0, mdmp_pos)+'_'
  rfbase = strmid(filename, slashisat+1, mdmp_pos-slashisat-1)+'_'
  
  openw, lun, filename, /get_lun
  nfields = N_elements(names)
  printf, lun, '#point format(ASCII) V00'
  for i=0, 3 do begin
     thisi = i
     if i eq 3 then thisi = parti.index  ; make sure the 4th colums is what is selected in GUI
     printf, lun, '#datavar'+strcompress(i-3)+' '+strcompress(names[thisi], /remove_all)
  endfor

  for i=0L, Ntimesteps-1 do begin
     ts = these_grids[r[r[i]]].time
     printf, lun, strcompress(ts), ' '+ strcompress(i) + ' '+rfbase+string(i, format='(i5.5)')+'.dmp'
  endfor
  close, lun
  free_lun, lun

  typeind = where(*parti.names eq 'particle_type', count)
  if count ge 0 then fieldstoread = (*parti.names)[[0,1,2,parti.index, typeind]] $
  else fieldstoread = (*parti.names)[[0,1,2,parti.index]]

  cnt = 0L
  for i=0L, Ntimesteps-1 do begin ; write indivdual times into separate files
     thisfile = fbase+string(i, format='(i5.5)')+'.dmp'
;breaki

     openw, lun, thisfile, /get_lun
     if h[i] gt 1 then begin 
        ngrids = r[i+1]-r[i]
;        cg = get_particle_data(these_grids[r[r[i]]:r[(r[i+1]-1)]],
;        (*parti.names))
        cg = get_particle_data(these_grids[r[r[i]]:r[(r[i+1]-1)]], fieldstoread)
        ts = these_grids[r[r[i]]].time
;        printf, lun, 'datatime ', strcompress(i),'  # time:', strcompress(ts), ' ',strcompress(ngrids), ' grids'
        for j=0L,N_elements(cg)-1 do begin
           ca = cg[j]
           if ptr_valid(ca.data[0]) then nparticles = N_elements(*ca.data[0]) else nparticles=-1
           for k=0L,nparticles-1 do begin
              line = ''
              if typeind[0] ge 0 then ctype = (*ca.data[4])[k] else ctype = parti.type
              if ((parti.type eq 0) or (ctype eq parti.type)) and (cnt mod parti.every) eq 0 then begin
                 for ii=0, 3 do begin 
                    line = line + strcompress((*ca.data[ii])[k])
                 endfor
                 printf, lun, line
              endif
              cnt += cnt
           endfor
        endfor
        printf, lun, ''
     endif
     close, lun
     free_lun, lun
  endfor


return
end