[SPARK-7781] [MLLIB] gradient boosted trees.train regressor missing max bins

Author: Holden Karau <holden@pigscanfly.ca>

Closes #6331 from holdenk/SPARK-7781-GradientBoostedTrees.trainRegressor-missing-max-bins and squashes the following commits:

2894695 [Holden Karau] remove extra blank line
2573e8d [Holden Karau] Update the scala side of the pythonmllibapi and make the test a bit nicer too
3a09170 [Holden Karau] add maxBins to to the train method as well
af7f274 [Holden Karau] Add maxBins to GradientBoostedTrees.trainRegressor and correctly mention the default of 32 in other places where it mentioned 100

1 files changed, 14 insertions, 8 deletions

diff --git a/python/pyspark/mllib/tree.py b/python/pyspark/mllib/tree.py
index cfcbea573f..372b86a7c9 100644
--- a/python/pyspark/mllib/tree.py
+++ b/python/pyspark/mllib/tree.py
@@ -299,7 +299,7 @@ class RandomForest(object):
                  1 internal node + 2 leaf nodes. (default: 4)
         :param maxBins: maximum number of bins used for splitting
                  features
-                 (default: 100)
+                 (default: 32)
         :param seed: Random seed for bootstrapping and choosing feature
                  subsets.
         :return: RandomForestModel that can be used for prediction
@@ -377,7 +377,7 @@ class RandomForest(object):
                  1 leaf node; depth 1 means 1 internal node + 2 leaf
                  nodes. (default: 4)
         :param maxBins: maximum number of bins used for splitting
-                 features (default: 100)
+                 features (default: 32)
         :param seed: Random seed for bootstrapping and choosing feature
                  subsets.
         :return: RandomForestModel that can be used for prediction
@@ -435,16 +435,17 @@ class GradientBoostedTrees(object):
 
     @classmethod
     def _train(cls, data, algo, categoricalFeaturesInfo,
-               loss, numIterations, learningRate, maxDepth):
+               loss, numIterations, learningRate, maxDepth, maxBins):
         first = data.first()
         assert isinstance(first, LabeledPoint), "the data should be RDD of LabeledPoint"
         model = callMLlibFunc("trainGradientBoostedTreesModel", data, algo, categoricalFeaturesInfo,
-                              loss, numIterations, learningRate, maxDepth)
+                              loss, numIterations, learningRate, maxDepth, maxBins)
         return GradientBoostedTreesModel(model)
 
     @classmethod
     def trainClassifier(cls, data, categoricalFeaturesInfo,
-                        loss="logLoss", numIterations=100, learningRate=0.1, maxDepth=3):
+                        loss="logLoss", numIterations=100, learningRate=0.1, maxDepth=3,
+                        maxBins=32):
         """
         Method to train a gradient-boosted trees model for
         classification.
@@ -467,6 +468,8 @@ class GradientBoostedTrees(object):
         :param maxDepth: Maximum depth of the tree. E.g., depth 0 means
                  1 leaf node; depth 1 means 1 internal node + 2 leaf
                  nodes. (default: 3)
+        :param maxBins: maximum number of bins used for splitting
+                 features (default: 32) DecisionTree requires maxBins >= max categories
         :return: GradientBoostedTreesModel that can be used for
                    prediction
 
@@ -499,11 +502,12 @@ class GradientBoostedTrees(object):
         [1.0, 0.0]
         """
         return cls._train(data, "classification", categoricalFeaturesInfo,
-                          loss, numIterations, learningRate, maxDepth)
+                          loss, numIterations, learningRate, maxDepth, maxBins)
 
     @classmethod
     def trainRegressor(cls, data, categoricalFeaturesInfo,
-                       loss="leastSquaresError", numIterations=100, learningRate=0.1, maxDepth=3):
+                       loss="leastSquaresError", numIterations=100, learningRate=0.1, maxDepth=3,
+                       maxBins=32):
         """
         Method to train a gradient-boosted trees model for regression.
 
@@ -522,6 +526,8 @@ class GradientBoostedTrees(object):
                  contribution of each estimator. The learning rate
                  should be between in the interval (0, 1].
                  (default: 0.1)
+        :param maxBins: maximum number of bins used for splitting
+                 features (default: 32) DecisionTree requires maxBins >= max categories
         :param maxDepth: Maximum depth of the tree. E.g., depth 0 means
                  1 leaf node; depth 1 means 1 internal node + 2 leaf
                  nodes.  (default: 3)
@@ -556,7 +562,7 @@ class GradientBoostedTrees(object):
         [1.0, 0.0]
         """
         return cls._train(data, "regression", categoricalFeaturesInfo,
-                          loss, numIterations, learningRate, maxDepth)
+                          loss, numIterations, learningRate, maxDepth, maxBins)
 
 
 def _test():