Getting the default radio button value from a button group

Hello!

I'm making a gui with multiple button groups that define values which is to be used in a function triggered by a push button.

My problem is that when I want the default radio button in the button group, I must "activate" it by pressing another button first, and then choosing it, else the value ends up empty.

Simplification of the code:

function indata2_OpeningFcn(hObject, ~, handles, varargin)
    handles.output = hObject;

    % Update handles structure
    guidata(hObject, handles);

function RUNpush_Callback(~, eventdata, handles)

    St=get(handles.shiptype,'UserData');
    %Send values into function
    FunctionoutsideGUI(St)

%One of the button groups:      
function shiptype_SelectionChangeFcn(hObject, eventdata, handles)

    handles = guidata(hObject);
    switch get(eventdata.NewValue,'Tag') % Get Tag of selected object.
    case 'St1'
    st=1;

    case 'St2'
    st=2;
     end
   set(handles.shiptype,'UserData',st);
  guidata(hObject,handles)

Hope someone can help me, Im realy struggeling with this, and I want to get it rigth.

-Lina

Answer 1

[Matt Fig]

GUI_8 demonstrates this.

GUI_examples

[Lina]

Thank you for your reply, but by adapting my code to the one in GUI_8, matlab stoped recognicing my st values inside the switch. I tried moving

set(handles.shiptype,'UserData',st);

Into the case code, and swaping st for the value, but St in the push button ended up blank.

I tried adding a handel.st=0 in the opening function, and adapting the same swich code as in the example, but handles.st remains 0 even though I activale the radiobutton.

This is how i my code looks now:

function indata2_OpeningFcn(hObject, ~, handles, varargin)

set(handles.shiptype,'SelectionChangeFcn',@shiptype_SelectionChangeFcn);

   set(handles.shiptype,'SelectedObject',[]);  % No selection
    set(handles.shiptype,'Visible','on');
      handles.output = hObject;
      % Update handles structure
 guidata(hObject, handles);

function RUNpush_Callback(~, eventdata, handles)
          St=get(handles.shiptype,'UserData');
          %Send values into function
          FunctionoutsideGUI(St)%One of the button groups: 

function shiptype_SelectionChangeFcn(hObject, eventdata, handles)
          handles = guidata(hObject);
           switch findobj(get(hObject,'selectedobject'))             
            case 'St1'
             set(handles.shiptype,'UserData',1);    
            case 'St2'
             set(handles.shiptype,'UserData',2);
             end
           guidata(hObject,handles)

Any ideas?