April 9, 2011
Getting Started with Processing
See pages 170 and 171 of
http://oreilly.com/catalog/0636920000570/preview#preview
http://oreilly.com/catalog/9780596514556
http://oreilly.com/catalog/9780596514556/preview#preview
http://www.smashingmagazine.com/2007/08/02/data-visualization-modern-approaches/