To run Matlab demos: 

download all the files from this directory into your local computer
 (e.g. your U-drive)

to run a Matlab file (e.g. "vectors.m" file), double-click on it, this will open the file in the Program editor and
you will also get a Command window. Type "vectors" in the Comannd window.

the function "arrow3D.m" is authored by Shawn Arseneau, I made slight changes to the interface.