Massive slow down in mouseclick behaviour in APPDESIGNER compared to GUIDE

Hello. I am observing quite a difference in beahviour between GUIDE and appdesigner.

I have an image that I have created a mouseclick callback which once the image has been displaye din an axes component allows the user to click - this then records the click postion on the image and calculates a mean of a small area around this position.

In GUIDE I Do this:

    %Ensure x & y are integers (i.e. represent pixels)
    x=round(curX);    %Cur X is the current mouseclick x position
    y=round(curY);    %Cur Y is the current mouseclick y position
    setappdata(0,'curX',x);   %Save for later use
    setappdata(0,'curY',y);   %Save for later use

    hold on
    plot(x,y,'r+','MarkerSize',15,'LineWidth',1)   %Display on image where user has clicked.
    hold off;
    refresh 
    %Get Zoomed in image
    IMG =double( getimage(handles.axes1));         %Get image data
    delta=100;                                     %Halfwidth of ROI region to get mean on 

     ROI = IMG(y-delta:y+delta, x-delta:x+delta,:);%Get the ROI
     mm=mean2(ROI);                                %Perfrom the mean 
     
     %Displat ROI rectangle and text of mean on the image
     hold on
     rectangle('Position',[x-delta y-delta 2*delta 2*delta], 'EdgeColor','y','LineWidth',0.5);  
     text(x,y-delta-45,num2str(mm,'%.1f'),'FontSize',10,'Color','r', 'HorizontalAlignment','center')
     hold off
     

This occurs almost instantly, say <0.25s

When I have tried to do this using APPDESIGNER, the plotting of the point with a marker is quick, however the calculation of the mean of the ROI and drawing of the rectangle with text is very slow. In all it takes about 2s. I cannot figure out wht it takes so much longer.

                   z=app.UIAxes.CurrentPoint;
                   x=round(z(1,1));  y=round(z(1,2));
                   hold(app.UIAxes,'on');
                   plot(app.UIAxes,x,y,'b*'); drawnow
                   
                   I=getimage(app.UIAxes);              
                   Intensity=I(y,x);    %Intensity of image at point x,y

                   %Now get mean of square region centred on x,y 
                   delta=100;
                   ROI = I(y-delta:y+delta, x-delta:x+delta,:);
                   mn=mean(ROI(:));    %Have also tried mean2(ROI) - but no better
                   rectangle(app.UIAxes,'Position',[x-delta y-delta 2*delta 2*delta], 'EdgeColor','y','LineWidth',0.5); 
                   text(app.UIAxes,x,y-delta-45,num2str(mn,'%.1f'),'FontSize',12,'Color','r', 'HorizontalAlignment','center');
                   hold(app.UIAxes,'off');

[Adam]

Did you run the profiler on it to see which line(s) are taking longest? It may be that it won't highlight anything as some code does differ in speed and optimisations when the profiler is run, but it may help.

[Jason]

Here it is.

[Jason]

..and here's another 2 times I have run the profiler..

[Adam]

What is on the next level down, in ImageButtonDownCallback?

[Jason]

How do i find out. When i click on the profile link nothing happens, is that what you mean?

[Adam]

Yes, you should be able to click on all those blue links (and indeed the fact the top 3 are purple shows you have done) and it will take you donw to the details at the next level and so on and so on. In this case the time is mostly being spent in that ImageButtonDownCallback so we would need to see what the breakdown of that is.

In some cases you just end up with most of the time in 'Self time (built-ins, overhead, etc.)' when you drill down to the lower level, but usually it does point to actual lines of code.

[Jason]

Hi, nothing happens, no new lines open up.

[Jason]

So in an attempt to find out where the problem is, I have used tic & toc

        function ImageButtonDownCallback(app, source, eventargs)     
                   %profile on 
                   disp('----timing-----')
                  tic
                   delete(findobj(app.UIAxes, 'Marker', '*')); %Delete previous marker
                   delete(findobj(app.UIAxes, 'Type','rectangle')); %Delete previous rectangler
                   delete(findobj(app.UIAxes, 'Type','text')); %Delete previous text
                   z=app.UIAxes.CurrentPoint;
                   x=round(z(1,1));  y=round(z(1,2));
                   hold(app.UIAxes,'on');
                   plot(app.UIAxes,x,y,'b*'); 
                   drawnow                   
                   app.xy=[x,y];
                   
                   I=getimage(app.UIAxes);   
                   
                   Intensity=I(y,x);
                   ReportMessage(app,['x=',sprintf('%.0f',x),', y=',sprintf('%.0f',y),' Intensity=',sprintf('%.0f',Intensity)]);
                   %Now get mean of square region centred on x,y 
                   delta=100;
                   ROI = I(y-delta:y+delta, x-delta:x+delta,:);
                   mn=mean(ROI(:));
                   
                   %mn=getMeanOfROI(app,I,x,y,delta);
                   rectangle(app.UIAxes,'Position',[x-delta y-delta 2*delta 2*delta], 'EdgeColor','y','LineWidth',0.5); 
                   text(app.UIAxes,x,y-delta-45,num2str(mn,'%.1f'),'FontSize',12,'Color','r', 'HorizontalAlignment','center');
                  toc
                   hold(app.UIAxes,'off');drawnow
                  toc
                  

and here are the values.

----timing-----
Elapsed time is 0.537646 seconds.
Elapsed time is 2.075554 seconds.

So 1.5s just to do the last line

hold(app.UIAxes,'off');drawnow

[Adam]

Yeah, draw now can be very slow, depending what is in the figure. I haven't used appdesigner much, but when I did it does seem generally slower than GUIDE, to first launch the UI at least, which is a lot down to drawing it so it doesn't surprise me if this is quicker from a GUIDE GUI.

[Jason]

But the first drawnow seems to be OK