anchor.diff:      get_frequencies(T,  [{{Lower,Upper},Cnt+Num}|Acc]);
   get_frequencies(L=[{I,_Num}|_], [Ah={{_Lower,Upper},_Cnt}|Acc]) when I>Upper ->
       [Ah | get_frequencies(L,Acc)];
  +get_frequencies([I|T], Acc) when is_integer(I) ->
  +    get_frequencies([{I,1}|T], Acc);
   get_frequencies([], Acc) -> 
       Acc.
   
  
positive.code: 	 || {Interval={Rlow,Rhigh},Val,Percent} <- Fs],
  	io:format('~*c    ~*c~n',[2*Npos_range,32,Npos_value+2,$-]),
  	io:format('~*c      ~*w~n',[2*Npos_range,32,Npos_value,SumVal])
          %%,io:format('L=~p~n',[L])
      catch
  	C:E ->
  	    io:format('*** Faild printing (~p:~p) for~n~p~n',[C,E,L])
  
negative.code: print_frequencies() -> print_frequencies(10).
  
  print_frequencies(Ngroups) -> fun([]) -> io:format('Empty list!~n',[]);
                                   (L ) ->
                                        try
                                            M = lists:last(L),
                                            Max = if is_integer(M) -> M;
                                                     is_tuple(M) -> element(1,L)
                                                  end,
                                            print_frequencies(L,Ngroups,0,Max)
                                        catch
                                            C:E:S ->
                                                ct:pal("~p:~p ~p:~p~n~p~n~p",[?MODULE,?LINE,C,E,S,L])
                                        end
                                end.
  
  print_frequencies(Ngroups, MaxValue) -> fun(L) -> print_frequencies(L,Ngroups,0,MaxValue) end.
  
  print_frequencies(L, N, Min, Max) when N>Max -> print_frequencies(L++[{N,0}], N, Min, N);
  print_frequencies(L, N, Min, Max0) ->
      try
          Interval = round((Max0-Min)/N),
          Max = Max0 + (Max0 rem Interval),
  	IntervalUpperLimits = 
  	    lists:reverse(
  	      [Max | tl(lists:reverse(lists:seq(Min,Max,Interval)))]
  	     ),
  	{Acc0,_} = lists:mapfoldl(fun(Upper,Lower) -> 
  					  {{{Lower,Upper},0}, Upper+1}
  				  end, hd(IntervalUpperLimits), tl(IntervalUpperLimits)),
          Fs0 = get_frequencies(L, Acc0),
  	SumVal = lists:sum([V||{_,V}<-Fs0]),
  	Fs = with_percentage(Fs0, SumVal),
  	Mean = mean(L),
  