Problem with GUI when trying to run it

function Speed_Callback(hObject, eventdata, handles)
user_entry=str2double(get(hObject,'string'));
if isnan(user_entry)
  errordlg('You must enter a numeric value','Bad Input','modal')
  uicontrol(hObject)
 return
end
% Proceed with callback
% hObject    handle to Speed (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% Hints: get(hObject,'String') returns contents of Speed as text
%        str2double(get(hObject,'String')) returns contents of Speed as a double

% --- Executes during object creation, after setting all properties.
function Speed_CreateFcn(hObject, eventdata, handles)
% hObject    handle to Speed (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end

% --- Executes on button press in Calculate.
function Calculate_Callback(hObject, eventdata, handles)
string=get(Speed_Callbackhandle,'user_entry');
% hObject    handle to Calculate (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA) 
user_entry=str2double(get(handles.Speed_Callback,'string')); % for example
user_entry =h;
Newfunction (h)

I am not understanding why I am still getting error messages

??? Undefined function or variable 'Speed_Callbackhandle'.

Error in ==> Stallfunction>Calculate_Callback at 105 string=get(Speed_Callbackhandle,'user_entry');

Error in ==> gui_mainfcn at 96 feval(varargin{:});

Error in ==> Stallfunction at 42 gui_mainfcn(gui_State, varargin{:});

Error in ==> @(hObject,eventdata)Stallfunction('Calculate_Callback',hObject,eventdata,guidata(hObject))

??? Error while evaluating uicontrol Callback

Answer 1

[Walter Roberson]

http://matlab.wikia.com/wiki/FAQ#How_can_I_share_data_between_callback_functions_in_my_GUI.3F

[Achchuthan Ganeshanathan]

I am trying to use handles to define the input from the user, does handles need to be defined at the start where it says

handles.output=hObject

[Walter Roberson]

At the end of your first routine, add

handles.user_entry = user_entry;
guidata(hObject, handles);

Then replace your last callback code with

h = handles.user_entry;
NewFunction(h);

[Achchuthan Ganeshanathan]

I have done as you said but I keep getting errors that user_entry is not defined

% --- Executes just before Stallfunction is made visible.
function Stallfunction_OpeningFcn(hObject, ~, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% varargin   command line arguments to Stallfunction (see VARARGIN)
% Choose default command line output for Stallfunction
handles.user_entry = user_entry;

% Update handles structure
guidata(hObject, handles);

% UIWAIT makes Stallfunction wait for user response (see UIRESUME)
% uiwait(handles.figure1);

I have inserted the code at the end of the first routine