org.apache.ignite.ml.tree.impurity.mse

Class MSEImpurityMeasure

java.lang.Object

org.apache.ignite.ml.tree.impurity.mse.MSEImpurityMeasure

All Implemented Interfaces:

Serializable, Comparable<MSEImpurityMeasure>, ImpurityMeasure<MSEImpurityMeasure>

public class MSEImpurityMeasure
extends Object
implements ImpurityMeasure<MSEImpurityMeasure>

Mean squared error (variance) impurity measure which is calculated the following way: \frac{1}{L}\sum_{i=0}^{n}(y_i - \mu)^2.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
MSEImpurityMeasure(double leftY, double leftY2, long leftCnt, double rightY, double rightY2, long rightCnt) Constructs a new instance of mean squared error (variance) impurity measure.

Method Summary

Modifier and Type	Method and Description
MSEImpurityMeasure	add(MSEImpurityMeasure b) Adds the given impurity to this.
long	getLeftCnt()
double	getLeftY()
double	getLeftY2()
long	getRightCnt()
double	getRightY()
double	getRightY2()
double	impurity() Calculates impurity measure as a single double value.
MSEImpurityMeasure	subtract(MSEImpurityMeasure b) Subtracts the given impurity for this.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.ignite.ml.tree.impurity.ImpurityMeasure

compareTo

Constructor Detail

MSEImpurityMeasure

public MSEImpurityMeasure(double leftY,
                          double leftY2,
                          long leftCnt,
                          double rightY,
                          double rightY2,
                          long rightCnt)

Constructs a new instance of mean squared error (variance) impurity measure.

Parameters:

leftY - Sum of all elements in the left part.

leftY2 - Sum of all squared elements in the left part.

leftCnt - Number of elements in the left part.

rightY - Sum of all elements in the right part.

rightY2 - Sum of all squared elements in the right part.

rightCnt - Number of elements in the right part.

Method Detail

impurity

public double impurity()

Calculates impurity measure as a single double value.

Specified by:

impurity in interface ImpurityMeasure<MSEImpurityMeasure>

Returns:

Impurity measure value.

add

public MSEImpurityMeasure add(MSEImpurityMeasure b)

Adds the given impurity to this.

Specified by:

add in interface ImpurityMeasure<MSEImpurityMeasure>

Parameters:

b - Another impurity.

Returns:

Sum of this and the given impurity.

subtract

public MSEImpurityMeasure subtract(MSEImpurityMeasure b)

Subtracts the given impurity for this.

Specified by:

subtract in interface ImpurityMeasure<MSEImpurityMeasure>

Parameters:

b - Another impurity.

Returns:

Difference of this and the given impurity.

getLeftY

public double getLeftY()

getLeftY2

public double getLeftY2()

getLeftCnt

public long getLeftCnt()

getRightY

public double getRightY()

getRightY2

public double getRightY2()

getRightCnt

public long getRightCnt()