Creating a popup menu through a function.

I am creating a pop up menu in matlab to find different things related to probability the function needs compute the Sum of probabilities if selcted and return for the user to make another choice and end if the user selects quit. I am not sure if I am doing this correctly at all. just looking for some pointers to ensure I am on the correct path. I am also trying to avoid using GUI if possible

This is my code so far:

function y = p3(X,P)
    countX = numel(X);
    countP = numel(P);
    if countX~=countP
      error('Different number of outcomes and probabilities');
    end
    if countX == countP
        h_fig = figure;
 h_popup = uicontrol(...
        'Style','popupmenu',...
        'String',{'Sum of Probabilities','Expected Value','Variance','Standard Deviation', 'Quit'},...
        'Callback',@mypopup_fcn,...
        'Units','normalized',...
        'Position',[0 0.5 1 0.5]);
 h_textbox = uicontrol(...
        'Style','edit',...
        'Units','normalized',...
        'Position',[0 0 1 0.5]);
 function changetype(hObj,~)
 case 1
     s = sum(P);
     h_textbox = ('The sum of the probabilities are ')
    end



    
        
end

[Jan]

"I am also trying to avoid using GUI if possible" - there are no popup menus without a GUI. So what does this mean?

The function changeType is not used, but mypopup_fcn is missing.

A case 1 requires a switch command before.

h_textbox = ('The sum of the probabilities are ')

I assume you mean:

h_textbox.String = sprintf('The sum of the probabilities are %g', s);