ParkJun (ELKI: Environment for DeveLoping KDD-Applications Supported by Index-Structures)

java.lang.Object
- elki.clustering.kmedoids.initialization.ParkJun<O>

Type Parameters:

O - Object type for KMedoids initialization

All Implemented Interfaces:

KMeansInitialization, KMedoidsInitialization<O>
```
@Priority(-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 ParkJun<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 Description

static class ParkJun.Par<V>
Parameterization class.

Field Summary

Fields
Modifier and Type Field Description

private static elki.logging.Logging LOG
Class logger.

Constructor Summary

Constructors
Constructor Description

ParkJun()
Constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`double[][]`	`chooseInitialMeans(elki.database.relation.Relation<? extends elki.data.NumberVector> relation, int k, elki.distance.NumberVectorDistance<?> distance)`	Choose initial means
`elki.database.ids.DBIDs`	`chooseInitialMedoids(int k, elki.database.ids.DBIDs ids, elki.database.query.distance.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 elki.logging.Logging LOG
```
    Class logger.
- Constructor Detail
  - ParkJun
```
public ParkJun()
```
    Constructor.
- Method Detail
  - chooseInitialMeans
```
public double[][] chooseInitialMeans(elki.database.relation.Relation<? extends elki.data.NumberVector> relation,
                                     int k,
                                     elki.distance.NumberVectorDistance<?> distance)
```
    Description copied from interface: KMeansInitialization
    
    Choose initial means
    
    Specified by:
    
    chooseInitialMeans in interface KMeansInitialization
    
    Parameters:
    
    relation - Relation
    
    k - Parameter k
    
    distance - Distance function
    
    Returns:
    
    List of chosen means for k-means
  - chooseInitialMedoids
```
public elki.database.ids.DBIDs chooseInitialMedoids(int k,
                                                    elki.database.ids.DBIDs ids,
                                                    elki.database.query.distance.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