anchor.diff:  
   handle_call({ clear, Stat }, _From, Stats) ->
   	{ reply, ok, reset(Stats,Stat) };
  +
  +handle_call({ sum, Stat }, _From, Stats = #stats{ windows = Windows }) ->
  +	case proplists:lookup(Stat,Windows) of 
  +		{ Stat, Values } -> Sum = lists:foldl(fun(A,B) -> A+B end, 0, Values);
  +		none -> Sum = 0
  +	end,
  +	{ reply, Sum, Stats };
  +
  +handle_call({ avg, Stat }, _From, Stats = #stats{ windows = Windows }) ->
  +	case proplists:lookup(Stat,Windows) of 
  +		{ Stat, Values } -> Avg = lists:foldl(fun(A,B) -> A+B end, 0, Values)/length(Values);
  +		none -> Avg = 0
  +	end,
  +	{ reply, Avg, Stats };
   
   handle_call(Message,_From,Stats) ->
   	io:format("[stats] unknown message ~p~n", [ Message ]),
  
positive.code: -author({ "David J Goehrig", "dave@dloh.org" }).
  -copyright(<<"© 2016 David J Goehrig"/utf8>>).
  -behavior(gen_server).
  -export([ start_link/0, stop/0, log/2, dump/0, allot/2, clear/1 ]).
  -export([ code_change/3, handle_call/3, handle_cast/2, handle_info/2, init/1,
  	terminate/2 ]).
  
  
negative.code: clear(Stat) ->
  	gen_server:call(?MODULE, { clear, Stat }).
  
  sum(Stat) ->
  	gen_server:call(?MODULE, { sum, Stat }).
  
  average(Stat) ->
  	gen_server:call(?MODULE, { avg, Stat }).
  
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  % Private APU
  %
  