Package elki.clustering.silhouette

Class PAMSIL.Instance

java.lang.Object

elki.clustering.silhouette.PAMSIL.Instance

Direct Known Subclasses:

PAMMEDSIL.Instance

Enclosing class:

PAMSIL<O>

protected static class PAMSIL.Instance
extends java.lang.Object

Instance for a single dataset.

Author:

Erich Schubert

Field Summary

Fields

Modifier and Type	Field	Description
(package private) WritableIntegerDataStore	assignment	Cluster mapping.
(package private) DistanceQuery<?>	distQ	Distance function to use.
(package private) DBIDs	ids	Ids to process.
(package private) WritableIntegerDataStore	scratch	Scratch cluster mapping.
(package private) WritableDoubleDataStore	silhouettes	Store the per-point silhouette scores for plotting.

Constructor Summary

Constructors

Constructor	Description
Instance(DistanceQuery<?> distQ, DBIDs ids, WritableIntegerDataStore assignment)	Constructor.

Method Summary

Modifier and Type	Method	Description
protected void	assignToNearestCluster(ArrayDBIDs medoids)	Assign each object to the nearest cluster.
protected void	reassignToNearestCluster(IntegerDataStore prev, WritableIntegerDataStore assignment, ArrayDBIDs medoids, int pi, DBIDRef h)	Assign each object to the nearest cluster when replacing one medoid.
protected double	run(ArrayModifiableDBIDs medoids, int maxiter)	Run the PAMSIL optimization phase.
protected double	silhouette(IntegerDataStore assignment, int k)	Evaluate the average Silhouette of the current cluster assignment
DoubleDataStore	silhouetteScores()

Methods inherited from class java.lang.Object

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

Field Detail

ids

DBIDs ids

Ids to process.

distQ

DistanceQuery<?> distQ

Distance function to use.

assignment

WritableIntegerDataStore assignment

Cluster mapping.

scratch

WritableIntegerDataStore scratch

Scratch cluster mapping.

silhouettes

WritableDoubleDataStore silhouettes

Store the per-point silhouette scores for plotting.

Constructor Detail

Instance

public Instance(DistanceQuery<?> distQ,
                DBIDs ids,
                WritableIntegerDataStore assignment)

Constructor.

Parameters:

distQ - Distance query

ids - IDs to process

assignment - Cluster assignment

Method Detail

run

protected double run(ArrayModifiableDBIDs medoids,
                     int maxiter)

Run the PAMSIL optimization phase.

Parameters:

medoids - Initial medoids list

maxiter - Maximum number of iterations

Returns:

final Silhouette

assignToNearestCluster

protected void assignToNearestCluster(ArrayDBIDs medoids)

Assign each object to the nearest cluster.

Parameters:

medoids - Cluster medoids

silhouette

protected double silhouette(IntegerDataStore assignment,
                            int k)

Evaluate the average Silhouette of the current cluster assignment

Parameters:

assignment - cluster assignment

k - number of clusters (for memory allocation)

Returns:

Average silhouette width

reassignToNearestCluster

protected void reassignToNearestCluster(IntegerDataStore prev,
                                        WritableIntegerDataStore assignment,
                                        ArrayDBIDs medoids,
                                        int pi,
                                        DBIDRef h)

Assign each object to the nearest cluster when replacing one medoid.

Parameters:

prev - Previous assignment

assignment - New assignment

medoids - Previous cluster medoids

pi - Medoid position

h - New medoid

silhouetteScores

public DoubleDataStore silhouetteScores()