MATLAB: How to Stop Fmincon from GUI

fminconguiguidehobject;Optimization Toolboxstop

How to stop fmincon from a pushbutton in a Matlab Gui?

The explaination posted here at the botton does not work, and can not work, as hObject never is passed into the outputfunction

http://de.mathworks.com/help/optim/ug/optimization-options-reference.html#f11022

 function stop = outfun(x,optimValues,state)
 stop = false;
 % Check if user has requested to stop the optimization.
 stop = getappdata(hObject,'optimstop');

Is there a way to stop the execution of the fmincon algorithm from a Pushbutton? Thanks a lot. Ravi

Best Answer

Ravi - I suspect that the example is only meant to provide an idea of how to do this given that you could have created your GUI either using GUIDE or using the programmatic approach. If you are using GUIDE, then you can always pass in hObject as an additional input to the outfun. For example, suppose that you have a start push button to start the optimization where you create the options (for fmincon) and start the optimization. For example,

 function start_pushbutton(hObject, eventdata, handles)
 % do some stuff
 % create the options
 opts = optimoptions(@fmincon,'OutputFcn','{@outfun,hObject});
 % start the optimization

Then, you would change the function signature of your outfun to be

 function stop = outfun(x,optimValues,state,hObject)

Here, it is assumed that you have created the outfun in the same m-file as for your GUI. Now rather than using getappdata (which forces you to have called setappdata to update hObject with the state of stop), I would use guidata to get the handles structure as

 function stop = outfun(x,optimValues,state,hObject)
 stop = false;
 handles = guidata(hObject);
 if isfield(handles,'optimstop')
     stop = handles.optimstop;
 end

And so your stop button callback would look something like

 function stop_pushbutton(hObject, eventdata, handles)
 handles.optimstop = true;
 guidata(hObject,handles);

In the above we set the optimstop field and then save that change to the handles structure.

I haven't tried the above (since I don't have the Optimization Toolbox) but I think that it can be made to work for your implementation.

Related Solutions

MATLAB: How to continue from same line using toggle button gui

Sagar - I think that you want to avoid putting a while loop in your callback, because what will happen is that on subsequent calls to this callback (i.e. the toggling on or off of the button) the callback function will be added to the stack so that you could have multiple togglebutton1_Callback functions "piling up" on top of each other. This will most likely happen when the depressing of the toggle occurs before the 10 iterations of the for loop have completed.

Consider the following code that is based on your function from above

 function togglebutton1_Callback(hObject, eventdata, handles)
 % hObject    handle to togglebutton1 (see GCBO)
 % eventdata  reserved - to be defined in a future version of MATLAB
 % handles    structure with handles and user data (see GUIDATA)
 % Hint: get(hObject,'Value') returns toggle state of togglebutton1
 toggleState = get(hObject,'Value');
 handles.togglebutton1CbackCtr = handles.togglebutton1CbackCtr + 1;
 guidata(hObject,handles);
 if toggleState
    x = handles.togglebutton1CbackCtr;
    for k=1:10
        fprintf('Callback %d hi (iter=%d)\n',x,k);
        pause(1);
    end
 else
    x = handles.togglebutton1CbackCtr;
    for k=1:10
        fprintf('Callback %d waiting (iter=%d)\n',x,k);
        pause(1.0)
    end  
 end

So we are just going to print out the hi statement along with the counter for when that callback fired, along with the iteration of the loop. Note how the while loop has been replaced with a for loop (so that we don't become stuck) has its one print statement for waiting. Now we run the GUI and press the toggle and observe

 Callback 1 hi (iter=1)
 Callback 1 hi (iter=2)
 Callback 1 hi (iter=3)
 Callback 1 hi (iter=4)
 Callback 1 hi (iter=5)
 Callback 1 hi (iter=6)
 Callback 1 hi (iter=7)
 Callback 1 hi (iter=8)
 Callback 1 hi (iter=9)
 Callback 1 hi (iter=10)

Which is fine. Now let's try again, and depress the toggle after the third iteration.

 Callback 1 hi (iter=1)
 Callback 1 hi (iter=2)
 Callback 1 hi (iter=3)
 Callback 2 waiting (iter=1)
 Callback 2 waiting (iter=2)
 Callback 2 waiting (iter=3)
 Callback 2 waiting (iter=4)
 Callback 2 waiting (iter=5)
 Callback 2 waiting (iter=6)
 Callback 2 waiting (iter=7)
 Callback 2 waiting (iter=8)
 Callback 2 waiting (iter=9)
 Callback 2 waiting (iter=10)
 Callback 1 hi (iter=4)
 Callback 1 hi (iter=5)
 Callback 1 hi (iter=6)
 Callback 1 hi (iter=7)
 Callback 1 hi (iter=8)
 Callback 1 hi (iter=9)
 Callback 1 hi (iter=10)

We see that once the second callback has completed "waiting", then the first callback resumes. Now imagine pressing and depressing the toggle multiple 10 times in succession and you would see something like

 Callback 1 hi (iter=1)
 Callback 2 waiting (iter=1)
 Callback 3 hi (iter=1)
 Callback 4 waiting (iter=1)
 Callback 5 hi (iter=1)
 Callback 6 waiting (iter=1)
 Callback 7 hi (iter=1)
 Callback 8 waiting (iter=1)
 Callback 9 hi (iter=1)
 Callback 10 waiting (iter=1)
 ...
 Callback 10 waiting (iter=10)
 Callback 9 hi (iter=2)
 ...
 Callback 9 hi (iter=10)
 Callback 8 waiting (iter=2)
 ...
 Callback 8 waiting (iter=10) 
 Callback 7 hi (iter=2)
 ...
 Callback 7 hi (iter=10)
 Callback 6 waiting (iter=2)
 ...
 Callback 6 waiting (iter=10)
 Callback 5 hi (iter=2)
 ...
 Callback 5 hi (iter=10)
 Callback 4 waiting (iter=2)
 ...
 Callback 4 waiting (iter=10)
 Callback 3 hi (iter=2)
 ...
 Callback 3 hi (iter=10)
 Callback 2 waiting (iter=2)
 ...
 Callback 2 waiting (iter=10)
 Callback 1 hi (iter=2)
 ...
 Callback 1 hi (iter=10)

Now imagine what would happen if we continued using a while loop to "wait". We would never exit that loop and we would have all the waiting callbacks "stuck" on the stack. You can see this if you call dbstack each time the togglebutton1_Callback is called.

What you may want to do instead, is to use a timer that fires for (say) 10 iterations (once a second) if the toggle button is pressed. If the button is depressed, then we "pause" the timer and allow it to continue once the user presses the toggle again. See the attached GUI which has a "dangerous" toggle (as described above) and a "safe" toggle that uses a timer.

MATLAB: How to pass extra parameters to an output function in the Optimization Toolbox

An output function expects 3 input arguments:

stop = outfun(x, optimValues, state)

Thus, the anonymous function, which is the value of the 'OutputFcn' property in the call to OPTIMSET, should be defined as follows:

options = optimset('outputfcn',@(x,optimValues,state)outfun(x,optimValues,state,extraArg),'display','iter',... 
'Algorithm','active-set');

That is, @(x,optimValues,state)outfun(x,optimValues,state,extraArg) instead of @(x)outfun(x,extraArg).

Best Answer

Related Solutions

MATLAB: How to continue from same line using toggle button gui

MATLAB: How to pass extra parameters to an output function in the Optimization Toolbox

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