You can use the handles structure to get access the other widgets/controls from a callback. Usually, this structure is the third input parameter to all callbacks. For example, suppose that your GUI has a list box and a uitable (like your GUI), and that whenever you select a row in the listbox, then the table is populated with data that corresponds to this selected row. In the OpeningFcn of your GUI, you could do the following
function myGui_OpeningFcn(hObject, eventdata, handles, varargin)
handles.output = hObject;
% add five elements/selections to the list box
listElems = {};
for k=1:5
listElems = [listElems ; sprintf('Processing %d',k)];
end
set(handles.listbox1,'String',listElems,'Value',1);
% set the uitable to a 4x3 table
colNames = {'Column 1','Column 2','Column 3'};
rowNames = {'Row 1','Row 2','Row 3','Row 4'};
set(handles.uitable1,'ColumnName',colNames,'RowName',rowNames);
% generate some random data for each processing element
handles.data = randi(255,4,3,5);
% update the uitable with data corresponding to the first selection
set(handles.uitable1,'Data',handles.data(:,:,1));
guidata(hObject, handles);
Since we have a 4x3 table, and 5 selections in the listbox, we create a random 4x3x5 matrix of data.
Now, in the listbox callback, whenever the user selects the kth element, we populate the uitable with the kth set of data
function listbox1_Callback(hObject, eventdata, handles)
% get the ID of the selected row
selectionId = get(hObject,'Value');
% update the uitable
set(handles.uitable1,'Data',handles.data(:,:,selectionId));
Note how we use handles to get both the randomly generated data, and the handle to the uitable, so that we can update the latter with the former. You would do something similar in the callbacks to your + and - buttons.
