scikit-learn/scikit-learn — pull request #3207 by ndawe (2014-05-27 11:48:39+00:00)
Title: [MRG] tree: add min_fraction_leaf stopping criterion

This PR adds a new decision tree stopping criterion: ``min_fraction_leaf`` that requires a minimum weighted fraction of the input samples to be present in all leaf nodes. This criterion is more appropriate than ``min_samples_leaf`` when you have weighted samples and many more samples of one class than another.