Use of the Pop-up menu in a GUI

Hi: I am developping a gui with the function pop-up menú but it does not work. This is the code:

function Vt_Callback(hObject, eventdata, handles)
% hObject    handle to Vt (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: contents = cellstr(get(hObject,'String')) returns Vt contents as cell array
%        contents{get(hObject,'Value')} returns selected item from Vt

switch get(handles.Vt_Callback,'Value')
    case ('Alta')
        Vt = 34;
    case ('Media')
        Vt = 23;
    case ('Baja')
        Vt = 18;
end
handles.data.Vt = Vt;
guidata(hObject, handles)
But when I run it, appears following message:

Vt =

   NaN
   NaN
   NaN

Warning: Rank deficient, rank = 0, tol = NaN. > In TDC>pushbutton3_Callback at 422 In gui_mainfcn at 96 In TDC at 42

I will appreciate very much to someone could explain me where is my error regards Willy

Answer 1

[Sabarinathan Vadivelu]

get(handles.Vt_Callback,'Value')

This returns the value.

Try using:

get(handles.Vt_Callback,'String')

[Guillermo Soriano]

Hi: Thank you for your quick response. But I got almost the same error: Vt =

   NaN
   NaN
   NaN

Warning: Rank deficient, rank = 0, tol = NaN. I did exactly what you sent. Regards Willy

Answer 2

[David Sanchez]

Instead of using the string of the selected item, use its position on the list:

switch get(handles.Vt_Callback,'Value')
    case 1 %('Alta')
        Vt = 34;
    case 2 %('Media')
        Vt = 23;
    case 3 %('Baja')
        Vt = 18;
end

[Guillermo Soriano]

Hi: thank you for your quick assistance. Unfortunately I got following message: Error: File: TDC.m Line: 224 Column: 19 Expression or statement is incomplete or incorrect.

Error in @(hObject,eventdata)TDC('pushbutton3_Callback',hObject,eventdata,guidata(hObject))

Error while evaluating uicontrol Callback

It refers to the statement : case %('Alta') Regards Willy