org.apache.commons.math3.ml.distance

Class EarthMoversDistance

java.lang.Object

org.apache.commons.math3.ml.distance.EarthMoversDistance

All Implemented Interfaces:

java.io.Serializable, DistanceMeasure

public class EarthMoversDistance
extends java.lang.Object
implements DistanceMeasure

Calculates the Earh Mover's distance (also known as Wasserstein metric) between two distributions.

Since:

3.3

See Also:

Earth Mover's distance (Wikipedia), Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
private static long	serialVersionUID Serializable version identifier.

Constructor Summary

Constructors

Constructor and Description
EarthMoversDistance()

Method Summary

Methods

Modifier and Type	Method and Description
double	compute(double[] a, double[] b) Compute the distance between two n-dimensional vectors.

Methods inherited from class java.lang.Object

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

Field Detail

serialVersionUID

private static final long serialVersionUID

Serializable version identifier.

See Also:

Constant Field Values

Constructor Detail

EarthMoversDistance

public EarthMoversDistance()

Method Detail

compute

public double compute(double[] a,
             double[] b)
               throws DimensionMismatchException

Compute the distance between two n-dimensional vectors.

The two vectors are required to have the same dimension.

Specified by:

compute in interface DistanceMeasure

Parameters:

a - the first vector

b - the second vector

Returns:

the distance between the two vectors

Throws:

DimensionMismatchException - if the array lengths differ.