How can I get this simple gui to allow the user to input data into a table, then save that input once they close the window?

What I'd like to have happen is that the user defines the size of a square matrix (for instance, 2 x 2). Then a new window would pop up and ask them for the individual data points, and then they would input the values into the correct spots on a table of the right size. I have gotten this to work fine up until the point where I actually need to retrieve the data to be used later. I cannot seem to "save" the data the user inputs. Here is what I have so far:

input = char(inputdlg('Please enter the order of the square matrix you wish to enter:'))
    n = str2num(input)
    matrix_data = cell(n,n)
matrix_input = figure('MenuBar','none','ToolBar','none',...
                 'Name','Row Reduction Assistant','NumberTitle','off','Position', [400 350 300 300]);
        matrix = uitable(matrix_input,'Data',matrix_data,...
            'Position', [42 65 220 220],...
            'ColumnEditable',true(1,10),...
            'ColumnName',[],... 
            'ColumnWidth', {30},...
            'FontSize', 15,...
            'RowName',[]);
        waitfor(gcf) 
            A_data = get(matrix_data,'Data');

When I do this, I get the error message:

Error using get
Conversion to double from cell is not possible.

Error in Test_file (line 14)
            A_data = get(matrix_data,'Data');

Please note that what I've got there isn't "neat" as far as GUI's go. I just threw together the basic structure, but I can't seem to figure out how to store the data.

Answer 1

[Walter Roberson]

              A_data = get(matrix,'Data');

[Chris Gnam]

This was what I originally tried, however that also does not work. When I replace my line of code with yours, what I get is:

Error using matlab.ui.control.Table/get
Invalid or deleted object.

Error in Test_file (line 14)
            A_data = get(matrix,'Data');

Any idea of another solution? Or what else can be done?