How do i stop the Timer Object from running
15 views (last 30 days)
Show older comments
Hey guys, I have this matlab function which is a timer function. It continuously reads numerical data from a text file (which updates every 10ms) and plot this data with time every (plot updates every second). In matlab, i type "timerPlot" to run the timer object function, but i have no idea how to stop it fro running. The only way i can stop it is if i close the plot window (which ends the timer via producing an error). Ive tried using stop(t) but it just says "Undefined function or variable 't'." Heres the code:
function [t] = livePlot(period, filename)
period = 1;
filename = 'C:\Program Files\...' %%Location of text file
close all;
t = timer('StartDelay', 1, 'Period', period, ...
'ExecutionMode', 'fixedRate');
%%timer object callback functions
t.StopFcn = {@stopFigure};
t.TimerFcn = {@updateFigure};
%%initialize timer object user data
d = get(t, 'UserData');
d.data = []; % array for the data to plot
axes('Position', [0 0 1 1], 'Visible', 'off');
d.axes_handle = axes('Position', [.2 .1 .7 .8]);
d.line_handle = plot(NaN,NaN);
d.fid = fopen(filename, 'r');
set(t, 'UserData', d);
start(t);
end
function stopFigure(obj, event)
% close function handle
d = get(obj, 'UserData');
fclose(d.fid);
delete(t)
disp('Timer has stopped.');
end
function updateFigure(obj, event)
d = get(obj, 'UserData');
% read new data from file
tmp = readFile(obj);
% append to array in user data
d.data = [d.data transpose(tmp)];
% update the plot
set(gcf, 'CurrentAxes', d.axes_handle);
set(d.line_handle, 'XData', 1:length(d.data), 'YData', d.data);
% store the timer object user-data
set(obj, 'UserData', d);
end
function [tmp] = readFile(obj)
% read binary data. file-ID is in the timer user-data
d = get(obj, 'UserData');
tmp = fscanf(d.fid, '%f', inf);
fprintf('Current file location : %d \n', ftell(d.fid));
fseek(d.fid, -1, 0); %%Reset the file position indicator back to beginning of file
fseek(d.fid, 1, 0);
set(obj, 'UserData', d);
end
Thanks.
0 Comments
Accepted Answer
Image Analyst
on 15 Jan 2014
You may find this useful:
%---------------------------------------------------------------------
function StopTimer(handles)
try
fprintf('Entering StopTimer...\n');
listOfTimers = timerfindall % List all timers, just for info.
% Get handle to the one timer that we should have.
if isempty(listOfTimers)
% Exit if there is no timer to turn off.
fprintf('There are no timers to turn off. Leaving StopTimer().\n');
return;
end
handleToTimer = getappdata(handles.figMainWindow, 'timerObj');
% Stop that timer.
stop(handleToTimer);
% Delete all timers from memory.
listOfTimers = timerfindall
if ~isempty(listOfTimers)
delete(listOfTimers(:));
end
fprintf('Left StopTimer and turned off all timers.\n');
catch ME
errorMessage = sprintf('Error in StopTimer().\nThe error reported by MATLAB is:\n\n%s', ME.message);
fprintf('%s\n', errorMessage);
WarnUser(errorMessage);
end
return; % from StopTimer
0 Comments
More Answers (0)
See Also
Categories
Find more on Environment and Settings in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!