PRO check_parents, grid_info

gin = N_elements(grid_info)
FOR i=0L,gin-1 DO BEGIN
   cg = grid_info[i]
   IF (cg.parent GE 1) THEN BEGIN
      pin = where(grid_info.parent EQ cg.num, count)
      if count gt 0 then begin
         pg = cg
         IF (vec_GT_vec(pg.left_edge, cg.left_edge) OR vec_LT_vec(pg.right_edge, cg.right_edge)) THEN BEGIN
            print, i, 'trouble'
;            break
         ENDIF
         for j=0L, count-1 do begin
            cc = grid_info[pin[j]]
            if vec_gt_vec(cc.parent_e_index, (pg.end_index-pg.start_index)) then begin
               print, 'parent end index in grid ', cc.num, ' is larger than parents:', pg.num, ' dimension', cc.parent_e_index, pg.dim
            endif
         endfor
      ENDIF
   endif
ENDFOR
RETURN
END

pro show_hierarchy_information, grid_info
  if N_elements(grid_info) eq 1 then return
  nlb = histogram(grid_info.level, reverse_indices=r)
  nl = N_elements(nlb)
  total_cell_count = 0L
  print, nlb
  for i=0,nl-1 do begin
     ind = r[r[i]:r[i+1]-1] 
     ncells = LONG(grid_info[ind].dim[0])* $
        grid_info[ind].dim[1]*grid_info[ind].dim[2]
     lcells = TOTAL(ncells)
     total_cell_count += lcells
     help_s = STRING(i, FORMAT = '(i2)')
     print, string(float(nlb[i]),FORMAT = '(I9)')+' grids on level '+help_s,$
            ' with ', STRING(lcells,FORMAT = '(i9)'), $
            ' (',STRING(lcells, FORMAT = '(E8.2)'),')', ' cells', $
            ' = ', string(float(lcells)^(1./3.), FORMAT = '(G6.4)'),'^3'
  endfor
  print, '                             --------------------------'
  print, 'total computational cells:', $
         STRING(total_cell_count, FORMAT = '(i11)'),$
         ' (',STRING(total_cell_count, FORMAT = '(E8.2)'),') =', $
         float(total_cell_count)^(1./3.),'^3'
  print, N_ELEMENTS(UNIQ(grid_info.parent)-1), ' parent grids'
return
end

function order_grids, grid_info
; order grids from low to high resolution:
; and insert levels numbers
  ngrids = N_ELEMENTS(grid_info) 
  IF (ngrids lt 1) THEN BEGIN
      print, 'order_grids: no grid information in grid_info:',$
             grid_info
      RETURN, grid_info
  ENDIF
  if ngrids eq 1 then return, grid_info ; nothing to do for sure

  num_of_levels = Max(grid_info.level)
  print, 'There are ', STRING(N_ELEMENTS(grid_info),FORMAT = '(i8)'), $
   ' grids on ', String(num_of_levels+1, FORMAT = '(i3)'), ' levels!'

  if num_of_levels eq 0 then return, grid_info ; nothing to do for sure

; do order 
  grid_info = grid_info[sort(grid_info.level)]

  RETURN, grid_info
END