Listbox showing variables with for loop

Hello, I have difficulties finding out a solution for my problem. So, the user is giving some data, which are some signals but the number of signals are not sure(may be 3 or even 15). So what I want to do is, after I get the variable with the number of signals(lets say the user puts 4 signals) and (I guess) with a for loop, show on my listbox:

signal 1

signal 2

signal 3

signal 4

and after the user selects one of this option(lets say he/she selects signal 3), I want to get some variable, which say that user choose signal 3. Is that possible? Did I make myself clear?

[Christopher Wallace]

What is the data type for the input data? Can you provide an sample data and the code you have tried so far?

[Image Analyst]

You did not make yourself clear. You could use inputdlg() to have the user type in the number, or you could use menu() to have the user click a button with the number on it. Is that what you meant? What do you want to do with the signal after it's selected, or is that irrelevant?

Answer 1

[Kostas Staios]

ΟΚ, so the user is inserting data as matrix (lets say a 2000x7 matrix), and every column is the signal response. So in the 2000x7 matrix, I have 7 signals; the signals can be more or less than 7. So, I want my listbox in GUI to show signal 1 till signal 7, and after the user choose lets say signal 3, to be able to plot only signal 3(the thrid column on my matrix). I havent done any code for that because I dont know how to make my GUI listbox that dynamic, showing that many variables with a for loop.

Answer 2

[Christopher Wallace]

There are a few ways to create a GUI. For this example I'm using GUIDE

I added three objects, a listbox and two push buttons.

When the 'Load Data' push button is pressed it creates sample user data as you have described above and then populates the listbox with items going "Signal 1" to "Signal n" based on the number of columns in the sample data.

When the 'Plot Data' button is pressed it will plot the data in the selected signals column from the user data.

Here are the callbacks for the two pushbuttons.

% --- Executes on button press in loadUserData.
function loadUserData_Callback(hObject, eventdata, handles)
% hObject    handle to loadUserData (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

handles.userData = randi(100, [2000,7]);
guidata(hObject, handles);

numOfSignals = size(handles.userData, 2);
signalNames = cell([1, numOfSignals]);
for i=1:numOfSignals
  signalNames{1,i} = ['Signal ', num2str(i)];
end
set(handles.listbox, 'String', signalNames);

% --- Executes on button press in pushbutton2.
function pushbutton2_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton2 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

selectedSignal = get(handles.listbox, 'Value');
plotFig = figure;
plot(handles.userData(:,selectedSignal));

[Kostas Staios]

Thank you very much, that was really helpful to understand how it works :)