Passing Parameters from GUI to Script

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Alan on 6 Sep 2012
I have GUI that I'm working on as a front end to an existing script. A partner of mine helps with the script, so I would like to keep it as a separate file. I'm attempting to pass the GUI handles as a struct object to the script, the script then takes the values from the handles and creates variables in the base workspace which will be used by a Simulink model.
When the user has input all the parameters, they hit a "Go" button which then calls the other script.
I've read other forum postings on this, and the closest I've come to success if the following callback:
% --- Executes on button press in Go.
function Go_Callback(hObject, eventdata, handles)
When the "Go" button is pressed, it generates an error:
Undefined variable "hnd" or function "hnd.Load_Sin".
Error in setup (line 66)
csim.motor3_for_test = get(hnd.Load_Sin,'Value'); %NO
It doesn't matter what object I try to call from hnd, the first one in the script always generates an error.
The odd thing is, if I then go an manually run setup.m, it runs fine.
It's acting like it's running setup.m before the assignin command, even though assignin is clearly before it.
I may have other end users who will run this script and I don't want them to have to jump through hoops to get it to run. What do I need to do so it executes correctly from pressing the Go button?

Accepted Answer

Matt Fig
Matt Fig on 6 Sep 2012
Edited: Matt Fig on 6 Sep 2012
If setup is a script, you are actually running it from in the callback. If that is o.k., try this:
function Go_Callback(hObject, eventdata, handles)
hnd = handles;
if not, you will have to do this:
function Go_Callback(hObject, eventdata, handles)
  1 Comment
Alan on 6 Sep 2012
D'oh. Just had a Homer Simpson moment.
Originally, I had this: csim.motor3_for_test = get(handles.Load_Sin,'Value');
Which is very similar. On searching the internet I thought it was because my script couldn't access the GUI's workspace.
What I didn't notice until I tried your suggestion, is that the error was NOT on the first line when I did that. I had typed a couple variables wrong further down the line - lower case where it should've been upper case! It was giving an error something like "nonexistent field" (not getting it anymore so I don't have it to copy).
What I still find odd is that it didn't seem to care about the case when I ran setup.m by itself - only when called from within the callback. That is truly bizarre.
Anyway, thank you!

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