A simple wrapper around the Scala implementation. `DataFrame` is used for serialization/deserialization. Methods that return `RDD`s are not supported in this PR.
davies If we recognize Scala's `Product`s in Py4J, we can easily add wrappers for Scala methods that returns `RDD[(Double, Double)]`. Is it easy to register serializer for `Product` in PySpark?
Author: Xiangrui Meng <meng@databricks.com>
Closes#4863 from mengxr/SPARK-6090 and squashes the following commits:
009a3a3 [Xiangrui Meng] provide schema
dcddab5 [Xiangrui Meng] add a basic BinaryClassificationMetrics to PySpark/MLlib
