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Interrupt running function with event in a GUI

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Mark T
Mark T on 31 Jan 2016
Answered: Abdelrhman Morsy on 26 Oct 2019
Hi, I want to use a GUI pushbutton to signal an event to a running function - in particular, to issue the 'keyboard' command in a misfit function which is being called by fminsearch (to investigate the state of the fitting process). Currently I use the following: Before calling fminsearch, main script opens a small GUI with a pushbutton with callback:
function pushbutton1_Callback(hObject, eventdata, handles)
global interrupt
...and in the misfit function:
global interrupt
if interrupt, keyboard, interrupt=false; end
This works, but I have to hammer the pushbutton repeatedly to get a response (waiting after one push doesn't seem to work). There is already a drawnow command in the misfit function on each call, which apparently should allow Matlab to process outstanding events, but this does not seem to improve matters (neither does a pause(0.01)).
Can someone suggest a good way to do this which might be more responsive?


Geoff Hayes
Geoff Hayes on 31 Jan 2016
Mark - what else is the misfit function doing (is this something that you have written)? Perhaps it is "busy" and once it finishes evaluating whatever it is doing, then it checks the interrupt flag. Please post the code for this function (or an outline of it) so that we can get a better idea of what may be causing the delay.
Mark T
Mark T on 1 Feb 2016
Hello, many thanks for your help. The behavior is not only when using fminsearch and my misfit function (v7.5.0 on Windows 7 x64 I should have mentioned). So, to nail it down, here is a complete stand-alone example:
function test_interrupt1b()
% Test a GUI button for interrupting another sub-routine
% with a keyboard command via "cheap" global variable
% Subfunctions defined below
hf=interrupt_button_sub1() % Create button
function subroutine_with_interrupt1b()
global interrupt
for loop=1:100 % any kind of loop
x=1:10; y=rand(size(x));
figure(2), clf, plot(x,y)
% drawnow % Same problem
pause(0.1) % Nice long pause
if interrupt, keyboard, interrupt=0; end
function hf=interrupt_button_sub1()
w=0.15; h=0.1; pos=[(1-w)/2 (1-h)/2 w h];
hpb=uicontrol('Parent', hf, 'style', 'pushbutton', ...
'String','Interrupt','units','normalized', ...
'position',[0 0 1 1],'fontsize',18);
function pushbutton_callback(hObject,callbackdata)
global interrupt, interrupt=1;
I hope that runs without any bugs on your computer. Do you also have the response problem? A single click-and-wait doesn't seem to do anything, as though the action/callback is ignored (not just queued). Many thanks for any advice. I can well imagine there is a recommended way to do this. Please keep in mind that in general, the subroutines will be separate functions. MT

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Answers (2)

Abdelrhman Morsy
Abdelrhman Morsy on 26 Oct 2019


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