timer doesn't work
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hello everybody,with this timer I wonder why stops and don't carry on to execute. what's wrong? I want webread to be refreshed every 60 secs. tks
t = timer('TimerFcn', 'stat=false; disp(''Timer!'')',...
'StartDelay',60);
start(t)
stat=true;
while(stat==true)
webread('https://www..etc...');
pause(1)
end
0 Comments
Accepted Answer
Benjamin Kraus
on 21 Feb 2023
Edited: Benjamin Kraus
on 21 Feb 2023
@Walter Roberson already pointed you to the documentation on how to Share Data Between Workspaces, which provides several ways to achieve your goal. I suggest reading that doc page.
function doStuff()
intervalInS=60;
everyNowAndThen = timer("Period",intervalInS,"ExecutionMode","fixedRate","TimerFcn",@refresh);
everyNowAndThen.start();
function refresh(~,~)
assignin('base','tbl',webread('https://api........CSV'))
end
end
The function webread('https://api........CSV') will be executed, and the result will be stored in the variable named tbl in the base workspace (i.e. workspace available at the command line).
Keep in mind that this means that as you are working, and as long as the timer is running, the variable tbl will continually be overwritten with the new data. Any other changes you make will be lost every time the timer executes.
Also keep in mind that if you are running other code when the timer is due to execute, your timer will wait until the other code is done. The reverse is also true, if your timer is running the webread command, no other MATLAB code will execute.
If your call to webread takes more than a fraction of a section, MATLAB will appear to hang every minute while webread is executing, which could be a pretty unplesant experience. I'm not sure if webread works with backgroundPool, but if you find yourself in this situation, you may want to look into backgroundPool to allow this code to run independently of your main MATLAB thread.
2 Comments
Walter Roberson
on 21 Feb 2023
timers potentially get control at the beginning of the each line of MATLAB code. But of course if you are doing a large vectorized operation or are calling a mex file it might be quite a while before the next matlab line is reached.
More Answers (3)
Sulaymon Eshkabilov
on 20 Feb 2023
Here it shows that it is working. An alternative way is to use [tic .. toc] to count time if this is the objective:
Tspan = 10; % Time span 10 seconds
t = timer('TimerFcn', 'stat=false; disp(''Timer!'')', 'StartDelay',Tspan);
start(t)
tic
stat=true;
while(stat==true)
webread('https://www.mathworks.com');
pause(1)
end
Tend = toc;
fprintf('Total time with [tic...toc]: %f \n', Tend)
3 Comments
Sulaymon Eshkabilov
on 20 Feb 2023
Here is how it can be attained:
Tspan = 240; % Time span 240 seconds
t = timer('TimerFcn', 'stat=false; disp(''Timer!'')', 'StartDelay', Tspan);
start(t)
Tupdated = 60;
tic
stat=true;
ii = 0;
while(stat==true)
ii=ii+1;
fprintf('WEB is read for %d time \n', ii);
DT={webread('https://www.mathworks.com')};
pause(Tupdated)
end
Tend = toc;
fprintf('Total time with [tic...toc]: %f \n', Tend)
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