anchor.diff:                "  \\draw[color=red!50!black,->] (-2cm, 0.5)"
                 "  -- (-1.5cm, 0.5) node[anchor=west] {global send};~n", []),
   
  -    draw_messages(File, Nodes, ScaleX, DrawTrace),
  +    draw_messages(File, Nodes, ScaleX, HaveRealTime, DrawTrace),
   
       io:format(
         File,
  
positive.code:                         [] -> NewDrawTrace;
                          _ ->
                              DoneTime = element(2, hd(DoneEvents)),
                              io:format(File,
                                        "\\draw[semithick] (~pcm, -~p)"
                                        " -- "
                                        " (~pcm, -~p) node[inner sep=1pt, anchor=south] {\\tiny ~p};~n",
                                        [RecvTime/ScaleX, DestNum/2,
                                         DoneTime/ScaleX, DestNum/2,
                                         DoneTime - RecvTime]),
                              lists:delete(hd(DoneEvents), NewDrawTrace)
                      end
              end;
  
negative.code: %% trace analysis
  -export([send_histogram/1]).
  -export([time_delta/1]).
  -export([to_texfile/2, to_texfile_no_time/2]).
  
  %% report tracing events from other modules
  -export([log_send/5]).
  