function ft_realtime_packettimer(cfg)

% FT_REALTIME_PACKETTIMER can be used to time the rate at which data can be processed

%

% Use as

% ft_realtime_packettimer(cfg)

% with the following configuration options

% cfg.bcifun = processing of the data (default = @bcifun_timer)

% cfg.npackets = the number of packets shown in one plot (default=1000)

% after reaching the end

% cfg.saveplot = if path is specified, first plot is saved (default=[]);

% cfg.rellim = y limits of subplot 1 (default = [-100 100])

%

% SEE ALSO:

% FT_REALTIME_PROCESS

% TO DO:

% jitter in het binnenhalen van de data; scatterplot!

% triggers sturen en herhalen (loop closen)

% tijd schatten waarin matlab nog kan processen

% Copyright (C) 2009, Marcel van Gerven

%

% $Id$

if ~isfield(cfg,'bcifun'), cfg.bcifun = @bcifun_timer; end

if ~isfield(cfg,'npackets'), cfg.npackets = 10^2; end

if ~isfield(cfg,'rellim'), cfg.rellim = [-1 1]; end

if ~isfield(cfg,'saveplot'), cfg.saveplot= []; end

close all;

f1 = figure();

set(f1,'units','normalized','outerposition',[0 0 1 1]);

% reset persistent variables

cfg.bcifun();

try

ft_realtime_process(cfg);

catch

fprintf('%s\n',lasterr);

close;

end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% BCIFUN_TIMER plots real time versus packet time

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

function bcifun_timer(cfg,data)

persistent startsample;

persistent olddf;

persistent idx;

if nargin == 0

idx = []; % reset persistent

return;

end

if isempty(idx)

tic;

startsample = data.endsample;

idx = 1;

olddf = 0;

return;

end

if mod(idx,cfg.npackets) == 1

xl = [floor(idx/cfg.npackets)*cfg.npackets+1 (floor(idx/cfg.npackets)+1)*cfg.npackets];

hold off

plot(xl,[0 0],'k--');

xlim(xl);

ylim(cfg.rellim);

xlabel('packet number');

ylabel('delay (sample time - real time)');

hold on;

end

cursample = data.endsample;

curtime = toc;

smptime = (cursample - startsample)/data.fsample;

df = smptime - curtime;

if df < 0

plot([idx-1 idx],[olddf df],'r');

else

plot([idx-1 idx],[olddf df],'g');

end

olddf = df;

title(sprintf('packet timing for %g s blocks in %d channels at sample frequency %d; sample time = %g, real time = %g, delay = %g',...

data.blocksize/data.fsample,length(data.label),data.fsample,smptime,curtime,smptime - curtime));

idx = idx + 1;

drawnow;

if idx==cfg.npackets && strcmp(cfg.saveplot,'yes')

saveas(gcf,cfg.saveplot,'jpg');

end