MATLAB app designer button

hi, in the app designer i created a 'start' button that starts the action of a long loops, and i want to create a 'stop' button that will immidietly stop the action of the first button and not waite until it finished the loops, is that possible?

Answer 1

[Ankit]

Please find attached *.zip file where you can see one example (refer below code)

properties (Access = public)
        stop_sim = false;        
end
        

    methods (Access = private)
        function stopSimulation(app)
            app.stop_sim = true;
            msgbox('simulation stopped');
        end
    
        function startSimulation(app)
            i = 0;
            while i<=1000000 && app.stop_sim == false
                app.display.Value = num2str(i);
                pause(0);
                i = i + 1;
            end
        end        
    end   

function StartButtonPushed(app, event)
            startSimulation(app)
end    

function StopButtonPushed(app, event)
            stopSimulation(app)
end

Once the user pushes the StopButtonPushed button, for which the function "stopSimulation" is a callback, then the app fetch the updated properties and the condition to app.stop_sim will be set to true and hence this allows the app to terminate the while loop before reaching 1000000 iterations.

[lital levy]

thank you,but its a long loop and it would stop only when it get to this line in the code, i need it to stop immidiatly when i push the button

[Ankit]

above function will break the loop as soon as you click the stop button right?

[Marek]

Hi, I built my program according to your example and observed behavior which I don't understand. Can you help me to understand this question?

When I put the Matlab optimization function (fmincon) inside the loop the stop button stops working. Namely, the stopSimulation function was performed AFTER the lop was finished.

By trial and error, I figured that changing pause(0) to pause(0.01) solved this problem. By trial and error, I figured that changing pause(0) to pause(0.01) solved this problem. The value of 0.005 seconds was too short. When I put 0.008 s the function made one or two additional iterations and stopped correctly. The one iteration takes 1 to 2 seconds, and I have a clear indicator of the actual stage, therefore I'm pretty sure that observation is correct.

The program works, but I would like to understand better why the value of pause time makes such a big difference.