org.apache.spark.mllib.tree.impurity

Interface Impurity

All Superinterfaces:

java.io.Serializable

public interface Impurity
extends scala.Serializable

Trait for calculating information gain. This trait is used for (a) setting the impurity parameter in Strategy (b) calculating impurity values from sufficient statistics.

Method Summary

Modifier and Type	Method and Description
double	calculate(double[] counts, double totalCount) :: DeveloperApi :: information calculation for multiclass classification
double	calculate(double count, double sum, double sumSquares) :: DeveloperApi :: information calculation for regression

Method Detail

calculate

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

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

:: DeveloperApi :: information calculation for regression

Parameters:

count - number of instances

sum - sum of labels

sumSquares - summation of squares of the labels

Returns:

information value, or 0 if count = 0