de.lmu.ifi.dbs.elki.algorithm.clustering.kmeans.initialization

Class ParkInitialMeans<O>

java.lang.Object

de.lmu.ifi.dbs.elki.algorithm.clustering.kmeans.initialization.ParkInitialMeans<O>

Type Parameters:

O - Object type for KMedoids initialization

All Implemented Interfaces:

KMeansInitialization, KMedoidsInitialization<O>

@Priority(value=-100)
 @Reference(authors="H.-S. Park, C.-H. Jun",
           title="A simple and fast algorithm for K-medoids clustering",
           booktitle="Expert Systems with Applications 36(2)",
           url="https://doi.org/10.1016/j.eswa.2008.01.039",
           bibkey="DBLP:journals/eswa/ParkJ09")
public class ParkInitialMeans<O>
extends java.lang.Object
implements KMeansInitialization, KMedoidsInitialization<O>

Initialization method proposed by Park and Jun.

It is easy to imagine that this approach can become problematic, because it does not take the distances between medoids into account. In the worst case, it may choose k duplicates as initial centers, therefore we cannot recommend this strategy, but it is provided for completeness.

Reference:

H.-S. Park, C.-H. Jun
A simple and fast algorithm for K-medoids clustering
Expert Systems with Applications 36(2)

Since:

0.7.5

Author:

Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ParkInitialMeans.Parameterizer<V> Parameterization class.

Field Summary

Fields

Modifier and Type	Field and Description
private static Logging	LOG Class logger.

Constructor Summary

Constructors

Constructor and Description
ParkInitialMeans() Constructor.

Method Summary

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

Methods inherited from class java.lang.Object

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

Field Detail

LOG

private static final Logging LOG

Class logger.

Constructor Detail

ParkInitialMeans

public ParkInitialMeans()

Constructor.

Method Detail

chooseInitialMeans

public double[][] chooseInitialMeans(Database database,
                                     Relation<? extends NumberVector> relation,
                                     int k,
                                     NumberVectorDistanceFunction<?> distanceFunction)

Description copied from interface: KMeansInitialization

Choose initial means

Specified by:

chooseInitialMeans in interface KMeansInitialization

Parameters:

database - Database context

relation - Relation

k - Parameter k

distanceFunction - 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>

Parameters:

k - Parameter k

ids - Candidate IDs.

distQ - Distance function

Returns:

List of chosen means for k-means