Invoke the function by calling with a transfer function as its argument.
>> mySys=tf([1 3],[1 5 12 8 0])
>> RLocusGui(mySys) %Invoke GUI
Thought Matlab can create root locus plots, it is still useful to sketch root locus plots by hand. The program, RLocsuGui, takes loop gain as input and then applies (and visually demonstrates) all of the rules that are typically used to sketch the plot by hand.
The program also creates a web page describing the rules as applied to the given loop gain.
The zip file contains a ".m" file and a ".fig" file. Put them both in a directory that is in the Matlab path.