org.apache.spark.mllib.tree.impurity

Class Entropy

Object

org.apache.spark.mllib.tree.impurity.Entropy

All Implemented Interfaces:

java.io.Serializable, Impurity

public class Entropy
extends Object
implements Impurity

:: Experimental :: Class for calculating entropy during binary classification.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
Entropy()

Method Summary

Methods

Modifier and Type	Method and Description
static double	calculate(double[] counts, double totalCount) :: DeveloperApi :: information calculation for multiclass classification
static double	calculate(double count, double sum, double sumSquares) :: DeveloperApi :: variance calculation
static org.apache.spark.mllib.tree.impurity.Entropy$	instance() Get this impurity instance.
static double	log2(double x)

Methods inherited from class Object

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

Methods inherited from interface org.apache.spark.mllib.tree.impurity.Impurity

calculate, calculate

Constructor Detail

Entropy

public Entropy()

Method Detail

log2

public static double log2(double x)

calculate

public static double calculate(double[] counts,
               double totalCount)

:: DeveloperApi :: information calculation for multiclass classification

Parameters:

counts - Array[Double] with counts for each label

totalCount - sum of counts for all labels

Returns:

information value, or 0 if totalCount = 0

calculate

public static double calculate(double count,
               double sum,
               double sumSquares)

:: DeveloperApi :: variance calculation

Parameters:

count - number of instances

sum - sum of labels

sumSquares - summation of squares of the labels

Returns:

information value, or 0 if count = 0

instance

public static org.apache.spark.mllib.tree.impurity.Entropy$ instance()

Get this impurity instance. This is useful for passing impurity parameters to a Strategy in Java.