title: Unbalanced classification using RandomForestClassifier in sklearn
body: <p>I have a dataset where the classes are unbalanced.  The classes are either '1' or '0' where the ratio of class '1':'0' is 5:1.  How do you calculate the prediction error for each class and the rebalance weights accordingly in sklearn with Random Forest, kind of like in the following link:  <a href="http://www.stat.berkeley.edu/~breiman/RandomForests/cc_home.htm#balance">http://www.stat.berkeley.edu/~breiman/RandomForests/cc_home.htm#balance</a></p>