一、欲實現的功能如下圖

二、實現步驟

2.1、需要用到Pop-Up Menu和座標軸控制元件，修改Pop-Up Menu的value值

 value=1，對應sin(x),以此類推。

2.2、進入回撥函式

function p1_Callback(hObject, eventdata, handles)
% hObject    handle to p1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: contents = cellstr(get(hObject,'String')) returns p1 contents as cell array
%        contents{get(hObject,'Value')} returns selected item from p1
var=get(handles.p1,'value');
x=0:0.01:2*pi;
axes(handles.axes1);
switch var
    case 1
        y=sin(x);
        plot(x,y);
    case 2
        y=cos(x);
        plot(x,y);
    case 3
        y=sin(x)+cos(x);
        plot(x,y);
end