"Inside the while loop, I want to check whether a certain push button has been pressed"
The callback function for the pushbutton should toggle a stored value from 0 to 1 (for example). How you store that value will depend on how your app was developed (guide, app designer, or uicontrol). Within the while-loop you can add a condition that checks the value of the variable altered by the pushbutton. If the value is 1, you can use "continue" to skip to the next iteration and you can set a flag that ends the while loop upon its next iteration. Alternatively, use "break" to exit the loop. You can then reset the stored value back to 0.
Note that the placement of this conditional within the while loop is important and you may want to place this condition at sevearal areas within the while loop. All execution of the while loop prior to the condition will still be executed.
If any of that is unclear, please add some detail so additional suggestions can be more concrete.
[update] Here's a functional demo you can run. It creates a simple GUI with two push buttons: Go & Stop. Press Go and watch the command window count to 1000 within a while-loop. Press stop to stop the process. Then press go again to restart from the beginning.
% Create GUI
h.fig = figure();
h.but1 = uicontrol(h.fig,'Style','PushButton','Units','Normalize','Position',[.1,.8,.2,.1],'String','Go');
h.but2 = uicontrol(h.fig,'Style','PushButton','Units','Normalize','Position',[.1,.6,.2,.1],'String','Stop');
h.but2Val = false; % Default stop-button-off
guidata(h.fig, h)
h.but1.Callback = {@button1CallbackFcn,h};
h.but2.Callback = {@button2CallbackFcn,h};
function button1CallbackFcn(hObj,event,handles)
% Responds to "go" button; counts to 1000 in command window
c = 1;
handles.but2Val = true;
while c < 1000
pause(0.1)
handles = guidata(hObj.Parent);
% Check if STOP buttons has been pressed
if handles.but2Val
c = 1000; % Short circuit the while-loop
handles.but2Val = false; % reset stop-button to off
guidata(hObj.Parent,handles)
continue % skip the rest of this loop
end
disp(c)
c = c+1;
end
end
function button2CallbackFcn(hObj,event,handles)
% Responds to "stop" button. Toggles the but2Val to TRUE
handles.but2Val = true;
guidata(hObj.Parent, handles)
end
For app designer
Here's a simple implementation of this idea in app designer. It requires a button that starts a process and a "state button" used to interrupt the process.
% Button pushed function: Button
function ButtonPushed(app, event)
% Count to 1000 unles interrupted
c = 1;
while c < 1000
pause(.1)
disp(c)
c = c+1;
% Check if state button was pressed (from false to true)
if app.StateButton.Value
c = 1001; % short circuit the while-loop
app.StateButton.Value = false; %rest the button state
end
end
end
