Package org.hipparchus.clustering.distance

Class EarthMoversDistance

java.lang.Object

org.hipparchus.clustering.distance.EarthMoversDistance

All Implemented Interfaces:

Serializable, DistanceMeasure

public class EarthMoversDistance
extends Object
implements DistanceMeasure

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

See Also:

• Earth Mover's distance (Wikipedia)
• Serialized Form

Constructor Summary

Constructors

Constructor	Description
EarthMoversDistance()	Empty constructor.

Method Summary

Modifier and Type	Method	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

Constructor Details

EarthMoversDistance

public EarthMoversDistance()

Empty constructor.

This constructor is not strictly necessary, but it prevents spurious javadoc warnings with JDK 18 and later.

Since:

3.0

Method Details

compute

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

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:

MathIllegalArgumentException - if the array lengths differ.