MATLAB : Step Plots [Urgent] I am stuck at very crucial stage. I want to generate the step plot which is generated using step command in simple MATLAB environment. However, I am trying to incorporate it in GUI where it should plot the step plot when clicked on the button. Following is the code for writing in normal MATLAB environment i.e. without GUI :- Code (Text): m=1000; b=50; num=; den=[m b]; cruise=tf(num,den); Kp = 600; Ki = 1; contr=tf([Kp Ki],[1 0]); sys_cl=feedback(contr*cruise,1); u=10; t=0:0.1:20; step(u*sys_cl,t) axis([0 20 0 10]) Taken from http://www.engin.umich.edu/class/ctms/examples/cruise/ccpid.htm I am trying to put the same thing under the button callback and it just doesnt show on the axes I have made. The axes just disappear and nothing happens. However, the simple plot command works all right. Following is my MATLAB code :- Code (Text): function pushbutton1_Callback(hObject, eventdata, handles) % hObject handle to pushbutton1 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA) axes(handles.axes1) k=get(handles.edit1,'String'); Kp=str2num(k); m=1000; b=50; u=10; num=; den=[m b]; cruise=tf(num,den); sys_cl=feedback(Kp*cruise,1); t=0:0.1:20; step(u*sys_cl,t); guidata(hObject, handles); So how do I plot the unit step plot on those axis ? Is there someway to plot the step function using plot ?