How to use guidata to save data in external MATLAB function?

Hi all,

I'm writing a GUI that uses external function m files. I call handles into the function to use values in a for loop. I eventually want to overwrite handles with the new value found from the for loop.

e.g.

handles.struct.variable = 0; % initialized in GUI main code
___________________________________________________________

    for x = 1:100
      variable = handles.struct.variable(x)
      variable = some equation/code;

      handles.struct.variable(x) = variable
      guidata(hObject, handles)            %<--------- this is my issue

    end

I pre-allocated the structure I'm using, but when I try to save the data using 'guidata(hObject, handles) I get an error:

"Undefined function or variable 'hObject'."

Does anyone know a way to save the data to handles in a function file written outside of the GUI?

Thanks!

Answer 1

[Walter Roberson]

To use guidata to update the master copy of the handles, you need to know at least one graphics object that is part of the figure that has the guidata attached to it. It can be anything inside the figure -- a uicontrol, an axes, a line, a context menu, anything. Perhaps you have an appropriate object inside the handles structure already.

If not, then you can use findobj(), provided you know something unique about some object that is inside the figure. You can findobj() to locate all figures, but if you don't know something about the one acting as your GUI then you might accidentally end up with multiple figures and pick the wrong one.

[rbme17]

Thank you for your response Walter. The m-files being used are nested under pushbutton2. They call some data saved in a structure in handles, and I only want to update those structures within handles. I tried using pushbutton2 as the handle/name without luck.

    guidata(pushbutton2, handles)

There's a long list of graphics (picture below). Sorry if I misunderstood you, but is there something else I should be looking for in findobj? I'm not so familiar with this function.

Thanks!

[Walter Roberson]

Try

      guidata(handles.pushbutton2, handles)

[rbme17]

Whoops! Seems to work fine now, thanks Walter!