As part of Enthought’s ongoing documentation effort I recently updated old some old wiki pages to use Traits 3.0 and Chaco 3.0. You can check out the new example, which models Van der Waals equation, in the Chaco 3.0 documenation and on the Enthought Open-Source wiki page. The direct link is here: http://code.enthought.com/projects/chaco/docs/html/user_manual/tutorial_2.html .