Getting numerical value from edit box in MATLAB

Question

I've designed a GUI with resize option in it. Where user is allowed to enter image size in 2 provided edit boxes.

function x_Callback(hObject, eventdata, handles)
% hObject    handle to x (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
user_entry_X = str2double(get(hObject,'string'));
if isnan(user_entry_X)
 errordlg('You must enter a numeric value','Bad Input','modal')
 uicontrol(hObject)
return
end

above code is for edit box X. If user gives non-numerical input it results in error. But I'm not getting how to fetch entered numeric values. I've a pushbutton named resize, on pressing that after entering numbers in edit box image should get resize. What should i use in my resize_callback function? please help me.

Solution

You can get the value of the edit box with

S = get(editBoxHandle, 'string');

If it's a numerical value, then convert it

N = str2num(S);

If you want to have only the digits within a string mixing letters and numbers, this code

S = '123abc456xyz';
N = cell2mat(regexp(S, '\d+', 'match')); 
disp(N)

gives N=123456 (from this SO answer).

Comments

[Chethan]

Thank you, well how can i clear the same edit box? I've a push button with name reset. after pressing that edit box should show zero values in the sense nothing should present.

[marsei]

The twin function of get will give you the control of the edit box content: set(editBoxHandle, 'string','') where '' stands for the empty string.