Decision tree example

http://www.patricklamle.com/Tutorials/Decision%20tree%20python/tuto_decision%20tree.html

http://www.patricklamle.com/Tutorials/Decision%20tree%20R/Decision%20trees%20in%20R%20using%20C50.html

http://gormanalysis.com/decision-trees-in-r-using-rpart/

https://triangleinequality.wordpress.com/2013/09/05/a-complete-guide-to-getting-0-79903-in-kaggles-titanic-competition-with-python/