Package elki.evaluation.clustering.internal

Class Silhouette<O>

java.lang.Object

elki.evaluation.clustering.internal.Silhouette<O>

Type Parameters:

O - Object type

All Implemented Interfaces:

Evaluator, ResultProcessor

@Reference(authors="P. J. Rousseeuw",
           title="Silhouettes: A graphical aid to the interpretation and validation of cluster analysis",
           booktitle="Journal of Computational and Applied Mathematics, Volume 20",
           url="https://doi.org/10.1016/0377-0427(87)90125-7",
           bibkey="doi:10.1016/0377-04278790125-7")
public class Silhouette<O>
extends java.lang.Object
implements Evaluator

Compute the silhouette of a data set.

Reference:

P. J. Rousseeuw
Silhouettes: A graphical aid to the interpretation and validation of cluster analysis
In: Journal of Computational and Applied Mathematics Volume 20, November 1987

TODO: keep all silhouette values, and allow visualization!

Since:

0.7.0

Author:

Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Silhouette.Par<O>	Parameterization class.

Field Summary

Fields

Modifier and Type	Field	Description
private Distance<? super O>	distance	Distance function to use.
private static java.lang.String	key	Key for logging statistics.
private static Logging	LOG	Logger for debug output.
private NoiseHandling	noiseOption	Option for noise handling.
private boolean	penalize	Penalize noise, if NoiseHandling.IGNORE_NOISE is set.
static java.lang.String	SILHOUETTE_NAME	Name of the silhouette result.

Constructor Summary

Constructors

Constructor	Description
Silhouette(Distance<? super O> distance, boolean mergenoise)	Constructor.
Silhouette(Distance<? super O> distance, NoiseHandling noiseOption, boolean penalize)	Constructor.

Method Summary

Modifier and Type	Method	Description
double	evaluateClustering(Relation<O> rel, DistanceQuery<O> dq, Clustering<?> c)	Evaluate a single clustering.
void	processNewResult(java.lang.Object result)	Process a result.

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

Logger for debug output.

SILHOUETTE_NAME

public static final java.lang.String SILHOUETTE_NAME

Name of the silhouette result.

See Also:

Constant Field Values

distance

private Distance<? super O> distance

Distance function to use.

noiseOption

private NoiseHandling noiseOption

Option for noise handling.

penalize

private boolean penalize

Penalize noise, if NoiseHandling.IGNORE_NOISE is set.

key

private static final java.lang.String key

Key for logging statistics.

Constructor Detail

Silhouette

public Silhouette(Distance<? super O> distance,
                  NoiseHandling noiseOption,
                  boolean penalize)

Constructor.

Parameters:

distance - Distance function

noiseOption - Handling of "noise" clusters.

penalize - noise, if NoiseHandling.IGNORE_NOISE is set.

Silhouette

public Silhouette(Distance<? super O> distance,
                  boolean mergenoise)

Constructor.

Parameters:

distance - Distance function

mergenoise - Flag to treat noise as clusters, instead of breaking them into singletons.

Method Detail

evaluateClustering

public double evaluateClustering(Relation<O> rel,
                                 DistanceQuery<O> dq,
                                 Clustering<?> c)

Evaluate a single clustering.

Parameters:

rel - Data relation

dq - Distance query

c - Clustering

Returns:

Average silhouette

processNewResult

public void processNewResult(java.lang.Object result)

Description copied from interface: ResultProcessor

Process a result.

Specified by:

processNewResult in interface ResultProcessor

Parameters:

result - Newly added result subtree.