org.apache.spark.mllib.tree.impurity

Class Variance

Object

org.apache.spark.mllib.tree.impurity.Variance

public class Variance
extends Object

Class for calculating variance during regression

Constructor Summary

Constructors

Constructor and Description
Variance()

Method Summary

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

Methods inherited from class Object

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

Constructor Detail

Variance

public Variance()

Method Detail

calculate

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

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)

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.Variance$ instance()

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

Returns:

(undocumented)