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

Constructor Summary

Constructors

Constructor and Description
EarthMoversDistance()

Method Summary

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

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

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.