org.apache.spark.mllib.tree
Class DecisionTree

Object
  org.apache.spark.mllib.tree.DecisionTree

All Implemented Interfaces:

java.io.Serializable, Logging

public class DecisionTree
extends Object
implements scala.Serializable, Logging

:: Experimental :: A class which implements a decision tree learning algorithm for classification and regression. It supports both continuous and categorical features. param: strategy The configuration parameters for the tree algorithm which specify the type of algorithm (classification, regression, etc.), feature type (continuous, categorical), depth of the tree, quantile calculation strategy, etc.

See Also:

Serialized Form

Constructor Summary

DecisionTree(Strategy strategy)

Method Summary

DecisionTreeModel	run(RDD<LabeledPoint> input) Method to train a decision tree model over an RDD
static DecisionTreeModel	train(RDD<LabeledPoint> input, scala.Enumeration.Value algo, Impurity impurity, int maxDepth) Method to train a decision tree model.
static DecisionTreeModel	train(RDD<LabeledPoint> input, scala.Enumeration.Value algo, Impurity impurity, int maxDepth, int numClasses) Method to train a decision tree model.
static DecisionTreeModel	train(RDD<LabeledPoint> input, scala.Enumeration.Value algo, Impurity impurity, int maxDepth, int numClasses, int maxBins, scala.Enumeration.Value quantileCalculationStrategy, scala.collection.immutable.Map<Object,Object> categoricalFeaturesInfo) Method to train a decision tree model.
static DecisionTreeModel	train(RDD<LabeledPoint> input, Strategy strategy) Method to train a decision tree model.
static DecisionTreeModel	trainClassifier(JavaRDD<LabeledPoint> input, int numClasses, java.util.Map<Integer,Integer> categoricalFeaturesInfo, String impurity, int maxDepth, int maxBins) Java-friendly API for DecisionTree$.trainClassifier(org.apache.spark.rdd.RDD, int, scala.collection.immutable.Map, java.lang.String, int, int)
static DecisionTreeModel	trainClassifier(RDD<LabeledPoint> input, int numClasses, scala.collection.immutable.Map<Object,Object> categoricalFeaturesInfo, String impurity, int maxDepth, int maxBins) Method to train a decision tree model for binary or multiclass classification.
static DecisionTreeModel	trainRegressor(JavaRDD<LabeledPoint> input, java.util.Map<Integer,Integer> categoricalFeaturesInfo, String impurity, int maxDepth, int maxBins) Java-friendly API for DecisionTree$.trainRegressor(org.apache.spark.rdd.RDD, scala.collection.immutable.Map, java.lang.String, int, int)
static DecisionTreeModel	trainRegressor(RDD<LabeledPoint> input, scala.collection.immutable.Map<Object,Object> categoricalFeaturesInfo, String impurity, int maxDepth, int maxBins) Method to train a decision tree model for regression.

Methods inherited from class Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.spark.Logging

initializeIfNecessary, initializeLogging, isTraceEnabled, log_, log, logDebug, logDebug, logError, logError, logInfo, logInfo, logName, logTrace, logTrace, logWarning, logWarning

Constructor Detail

DecisionTree

public DecisionTree(Strategy strategy)

Method Detail

train

public static DecisionTreeModel train(RDD<LabeledPoint> input,
                                      Strategy strategy)

Method to train a decision tree model. The method supports binary and multiclass classification and regression.

Note: Using DecisionTree$.trainClassifier(org.apache.spark.rdd.RDD, int, scala.collection.immutable.Map, java.lang.String, int, int) and DecisionTree$.trainRegressor(org.apache.spark.rdd.RDD, scala.collection.immutable.Map, java.lang.String, int, int) is recommended to clearly separate classification and regression.

Parameters:

input - Training dataset: RDD of LabeledPoint. For classification, labels should take values {0, 1, ..., numClasses-1}. For regression, labels are real numbers.

strategy - The configuration parameters for the tree algorithm which specify the type of algorithm (classification, regression, etc.), feature type (continuous, categorical), depth of the tree, quantile calculation strategy, etc.

Returns:

DecisionTreeModel that can be used for prediction

train

public static DecisionTreeModel train(RDD<LabeledPoint> input,
                                      scala.Enumeration.Value algo,
                                      Impurity impurity,
                                      int maxDepth)

Method to train a decision tree model. The method supports binary and multiclass classification and regression.

Note: Using DecisionTree$.trainClassifier(org.apache.spark.rdd.RDD, int, scala.collection.immutable.Map, java.lang.String, int, int) and DecisionTree$.trainRegressor(org.apache.spark.rdd.RDD, scala.collection.immutable.Map, java.lang.String, int, int) is recommended to clearly separate classification and regression.

Parameters:

input - Training dataset: RDD of LabeledPoint. For classification, labels should take values {0, 1, ..., numClasses-1}. For regression, labels are real numbers.

algo - algorithm, classification or regression

impurity - impurity criterion used for information gain calculation

maxDepth - Maximum depth of the tree. E.g., depth 0 means 1 leaf node; depth 1 means 1 internal node + 2 leaf nodes.

Returns:

DecisionTreeModel that can be used for prediction

train

public static DecisionTreeModel train(RDD<LabeledPoint> input,
                                      scala.Enumeration.Value algo,
                                      Impurity impurity,
                                      int maxDepth,
                                      int numClasses)

Method to train a decision tree model. The method supports binary and multiclass classification and regression.

Note: Using DecisionTree$.trainClassifier(org.apache.spark.rdd.RDD, int, scala.collection.immutable.Map, java.lang.String, int, int) and DecisionTree$.trainRegressor(org.apache.spark.rdd.RDD, scala.collection.immutable.Map, java.lang.String, int, int) is recommended to clearly separate classification and regression.

Parameters:

input - Training dataset: RDD of LabeledPoint. For classification, labels should take values {0, 1, ..., numClasses-1}. For regression, labels are real numbers.

algo - algorithm, classification or regression

impurity - impurity criterion used for information gain calculation

maxDepth - Maximum depth of the tree. E.g., depth 0 means 1 leaf node; depth 1 means 1 internal node + 2 leaf nodes.

numClasses - number of classes for classification. Default value of 2.

Returns:

DecisionTreeModel that can be used for prediction

train

public static DecisionTreeModel train(RDD<LabeledPoint> input,
                                      scala.Enumeration.Value algo,
                                      Impurity impurity,
                                      int maxDepth,
                                      int numClasses,
                                      int maxBins,
                                      scala.Enumeration.Value quantileCalculationStrategy,
                                      scala.collection.immutable.Map<Object,Object> categoricalFeaturesInfo)

Method to train a decision tree model. The method supports binary and multiclass classification and regression.

Note: Using DecisionTree$.trainClassifier(org.apache.spark.rdd.RDD, int, scala.collection.immutable.Map, java.lang.String, int, int) and DecisionTree$.trainRegressor(org.apache.spark.rdd.RDD, scala.collection.immutable.Map, java.lang.String, int, int) is recommended to clearly separate classification and regression.

Parameters:

input - Training dataset: RDD of LabeledPoint. For classification, labels should take values {0, 1, ..., numClasses-1}. For regression, labels are real numbers.

algo - classification or regression

impurity - criterion used for information gain calculation

maxDepth - Maximum depth of the tree. E.g., depth 0 means 1 leaf node; depth 1 means 1 internal node + 2 leaf nodes.

numClasses - number of classes for classification. Default value of 2.

maxBins - maximum number of bins used for splitting features

quantileCalculationStrategy - algorithm for calculating quantiles

categoricalFeaturesInfo - Map storing arity of categorical features. E.g., an entry (n -> k) indicates that feature n is categorical with k categories indexed from 0: {0, 1, ..., k-1}.

Returns:

DecisionTreeModel that can be used for prediction

trainClassifier

public static DecisionTreeModel trainClassifier(RDD<LabeledPoint> input,
                                                int numClasses,
                                                scala.collection.immutable.Map<Object,Object> categoricalFeaturesInfo,
                                                String impurity,
                                                int maxDepth,
                                                int maxBins)

Method to train a decision tree model for binary or multiclass classification.

Parameters:

input - Training dataset: RDD of LabeledPoint. Labels should take values {0, 1, ..., numClasses-1}.

numClasses - number of classes for classification.

categoricalFeaturesInfo - Map storing arity of categorical features. E.g., an entry (n -> k) indicates that feature n is categorical with k categories indexed from 0: {0, 1, ..., k-1}.

impurity - Criterion used for information gain calculation. Supported values: "gini" (recommended) or "entropy".

maxDepth - Maximum depth of the tree. E.g., depth 0 means 1 leaf node; depth 1 means 1 internal node + 2 leaf nodes. (suggested value: 5)

maxBins - maximum number of bins used for splitting features (suggested value: 32)

Returns:

DecisionTreeModel that can be used for prediction

trainClassifier

public static DecisionTreeModel trainClassifier(JavaRDD<LabeledPoint> input,
                                                int numClasses,
                                                java.util.Map<Integer,Integer> categoricalFeaturesInfo,
                                                String impurity,
                                                int maxDepth,
                                                int maxBins)

Java-friendly API for DecisionTree$.trainClassifier(org.apache.spark.rdd.RDD, int, scala.collection.immutable.Map, java.lang.String, int, int)

Parameters:

input - (undocumented)

numClasses - (undocumented)

categoricalFeaturesInfo - (undocumented)

impurity - (undocumented)

maxDepth - (undocumented)

maxBins - (undocumented)

Returns:

(undocumented)

trainRegressor

public static DecisionTreeModel trainRegressor(RDD<LabeledPoint> input,
                                               scala.collection.immutable.Map<Object,Object> categoricalFeaturesInfo,
                                               String impurity,
                                               int maxDepth,
                                               int maxBins)

Method to train a decision tree model for regression.

Parameters:

input - Training dataset: RDD of LabeledPoint. Labels are real numbers.

categoricalFeaturesInfo - Map storing arity of categorical features. E.g., an entry (n -> k) indicates that feature n is categorical with k categories indexed from 0: {0, 1, ..., k-1}.

impurity - Criterion used for information gain calculation. Supported values: "variance".

maxDepth - Maximum depth of the tree. E.g., depth 0 means 1 leaf node; depth 1 means 1 internal node + 2 leaf nodes. (suggested value: 5)

maxBins - maximum number of bins used for splitting features (suggested value: 32)

Returns:

DecisionTreeModel that can be used for prediction

trainRegressor

public static DecisionTreeModel trainRegressor(JavaRDD<LabeledPoint> input,
                                               java.util.Map<Integer,Integer> categoricalFeaturesInfo,
                                               String impurity,
                                               int maxDepth,
                                               int maxBins)

Java-friendly API for DecisionTree$.trainRegressor(org.apache.spark.rdd.RDD, scala.collection.immutable.Map, java.lang.String, int, int)

Parameters:

input - (undocumented)

categoricalFeaturesInfo - (undocumented)

impurity - (undocumented)

maxDepth - (undocumented)

maxBins - (undocumented)

Returns:

(undocumented)

run

public DecisionTreeModel run(RDD<LabeledPoint> input)

Method to train a decision tree model over an RDD

Parameters:

input - Training data: RDD of LabeledPoint

Returns:

DecisionTreeModel that can be used for prediction