For Loop within Matlab GUIDE

Question

I have Matlab GUI that uses push button that executes certain code. all of that works, except that when code reaches for loop, execution does not seem to enter that.

1) Any idea how for loop is implemented within framework of Matlab GUIDE code?
2) is there a way to debug GUI code ( only way I could was trough 'disp' statements,) using breakpoints, as when I run the GUI, breakpoints get removed.

after having read the solutions, I found that
(1) happened because the for loop index was not changing as length of array that I was indexing on, was not changing. I explain this in the code.
(2) My bad, I was putting breakpoints before running the GUI, when I did the other way around, it breaks fine.

% Opening func
function Regression_OpeningFcn(hObject, ~, handles, varargin)
NoiseMin = -12;
NoiseMax = 10;
NoiseRes = 2;
handles.noiseMin = NoiseMin;
handles.noiseMax = NoiseMax;
handles.noiseRes = NoiseRes;

%**this executed when value changed in edit text box***

function noiseMinDbEditText_Callback(~, ~, handles)
handles.noiseMin = str2num(get(handles.noiseMinDbEditText,'String'));

% When GUI is running, following shows change from -12 sucessfully 
disp(strcat('Noise Min = ',num2str(handles.noiseMin)));

function noiseMinDbEditText_CreateFcn(hObject, ~, ~) 
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor')) 
set(hObject,'BackgroundColor','white');
end

 %Similar code for noiseMax and noiseRes(not shown here)  

`% Here, code enters the Pushbutton callback

function StartRegressionPushButton_Callback(~, ~, handles)
snr_res = handles.noiseRes;
% here, snr_vecs still shows [-12 2 10]
snr_vecs = [handles.noiseMin:handles.noiseRes:handles.noiseMax];

So, basically, when GUI runs, entering and changing the values in text box corresponding to min, max and res snr variables shows me the change, but as soon as I enter the pushbutton dialog box, the changed values( that were captured in global variable "handles") do not show up as I break in the code there.
Any help with this? [for loop problem arose as I was indexing based on snr_vecs array, which is not changing, and so for loop was executing,but not as it should be]
sedy

Please provide detail description with your code. From above description i can't clearly identify the issue. — Karthick Rajan
I am not sure, but I think that is handled by the matlab main function. Alternatively the matlab gui may have a separate main loop. Anyway, looking in the gui main function it seems as if the function mainly sets up the figures and callbacks. The problem that breakpoints disappear when I run the gui is nothing I can reproduce. Have you tried restarting matlab? What OS are you using? Also, you are aware that the gui runs from when you set it up and until you close it, right? This means that no breakpoints can be set during that time. — patrik
@patrik yes,, it was stupid of me that I was putting breakpoint even before pressing the Run button. Once I run ,and the GUI appears, I am able to break into the code. Doing so I noticed the following: — user915783

rst rst · Accepted Answer · 2015-06-15T07:51:49

Using Matlab guide

Guide is basically only a tool to create fig. files. All you can do with guide you could do yourself programmatically. Creating ui-elements works by hand just as easy as with guide (I actually prefere creating gui elements programmatically, since I think guide is very poorly coded)...

Every guide-elements has its callbacks which have to be coded somewhere, usually (I think 100% of the time) the fig file has the same name as the .m file. Find the corresponding .m-file and go to the callback you are interessted in. There you can place breakpoints just as easy as in any other piece of code.

Note: you can even change the code without having to reopen the fig file!

For loops or anything that works in regular code works for ui-element code.

For Loop within Matlab GUIDE

2 Answers