scikit-learn/scikit-learn — pull request #2875 by arjoly (2014-02-19 16:27:04+00:00)
Title: [WIP] Faster depth-based tree builder by avoiding to split on known constant features in the sample subset

This is a resurrection of pr #2813. The idea is the same. However, here the invariant that the order of features known to be constant is enforced by copying data in an auxiliary array `constant_features`.