Package elki.clustering.kmeans.initialization

Class FarthestSumPoints<O>

java.lang.Object

elki.clustering.kmeans.initialization.AbstractKMeansInitialization

elki.clustering.kmeans.initialization.FarthestPoints<O>

elki.clustering.kmeans.initialization.FarthestSumPoints<O>

Type Parameters:

O - Object type for kmedoids and kmedians

All Implemented Interfaces:

KMeansInitialization, KMedoidsInitialization<O>

public class FarthestSumPoints<O>
extends FarthestPoints<O>

K-Means initialization by repeatedly choosing the farthest point (by the sum of distances to previous objects).

Note: this is less random than other initializations, so running multiple times will be more likely to return the same local minima.

Since:

0.6.0

Author:

Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	FarthestSumPoints.Par<V>	Parameterization class.

Field Summary

Fields inherited from class elki.clustering.kmeans.initialization.FarthestPoints

dropfirst

Fields inherited from class elki.clustering.kmeans.initialization.AbstractKMeansInitialization

rnd

Constructor Summary

Constructors

Constructor	Description
FarthestSumPoints(RandomFactory rnd, boolean dropfirst)	Constructor.

Method Summary

Modifier and Type	Method	Description
double[][]	chooseInitialMeans(Relation<? extends NumberVector> relation, int k, NumberVectorDistance<?> distance)	Choose initial means
DBIDs	chooseInitialMedoids(int k, DBIDs ids, DistanceQuery<? super O> distQ)	Choose initial means

Methods inherited from class elki.clustering.kmeans.initialization.AbstractKMeansInitialization

unboxVectors

Methods inherited from class java.lang.Object

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

Constructor Detail

FarthestSumPoints

public FarthestSumPoints(RandomFactory rnd,
                         boolean dropfirst)

Constructor.

Parameters:

rnd - Random generator.

dropfirst - Flag to discard the first vector.

Method Detail

chooseInitialMeans

public double[][] chooseInitialMeans(Relation<? extends NumberVector> relation,
                                     int k,
                                     NumberVectorDistance<?> distance)

Description copied from interface: KMeansInitialization

Choose initial means

Specified by:

chooseInitialMeans in interface KMeansInitialization

Overrides:

chooseInitialMeans in class FarthestPoints<O>

Parameters:

relation - Relation

k - Parameter k

distance - Distance function

Returns:

List of chosen means for k-means

chooseInitialMedoids

public DBIDs chooseInitialMedoids(int k,
                                  DBIDs ids,
                                  DistanceQuery<? super O> distQ)

Description copied from interface: KMedoidsInitialization

Choose initial means

Specified by:

chooseInitialMedoids in interface KMedoidsInitialization<O>

Overrides:

chooseInitialMedoids in class FarthestPoints<O>

Parameters:

k - Parameter k

ids - Candidate IDs.

distQ - Distance function

Returns:

List of chosen means for k-means