MATLAB step command
From ControlTheoryPro.com

Contents
1 Introduction to MATLAB's step command
MATLAB's step command plots the step response of the provided closed loop system on a figure. Technically the step command plots on an axes object but if user does not provide an axes handle as the first argument then MATLAB will create the plot on the currnet axis (using the gca command which will create a figure and axis objects if none exist).
2 Usage of MATLAB's step command
The easiest usage of the step command is as follows
>> step(cl)
where cl is a LTI object representing the closed loop system.
In order to plot the step response on a predefined axis the axis handle must be passed as the first argument such as
>> step(h, cl)
where h is the handle to the desired axis.
3 See Also
4 MATLAB Related Books