de.lmu.ifi.dbs.elki.algorithm.clustering.hierarchical

Class PointerHierarchyRepresentationResult

java.lang.Object

de.lmu.ifi.dbs.elki.result.AbstractHierarchicalResult

de.lmu.ifi.dbs.elki.result.BasicResult

de.lmu.ifi.dbs.elki.algorithm.clustering.hierarchical.PointerHierarchyRepresentationResult

All Implemented Interfaces:

HierarchicalResult, Result

Direct Known Subclasses:

PointerDensityHierarchyRepresentationResult

public class PointerHierarchyRepresentationResult
extends BasicResult

The pointer representation of a hierarchical clustering. Each object is represented by a parent object and the distance at which it joins the parent objects cluster. This is a rather compact and bottom-up representation of clusters, the class ExtractFlatClusteringFromHierarchy can be used to extract partitions from this graph. This class can also compute dendrogram positions, but using a faster algorithm than the one proposed by Sibson 1971, using only O(n log n) time due to sorting, but using an additional temporary array.

Since:

0.6.0

Author:

Erich Schubert

Field Summary

Fields

Modifier and Type	Field and Description
(package private) DBIDs	ids The DBIDs in this result.
(package private) DBIDDataStore	parent The parent DBID relation.
(package private) DoubleDataStore	parentDistance Distance to the parent object.
(package private) IntegerDataStore	positions Position storage, computed on demand.

Constructor Summary

Constructors

Constructor and Description
PointerHierarchyRepresentationResult(DBIDs ids, DBIDDataStore parent, DoubleDataStore parentDistance) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
DBIDs	getDBIDs() Get the clustered DBIDs.
DoubleDataStore	getParentDistanceStore() Get the distance to the parent.
DBIDDataStore	getParentStore() Get the parent DBID relation.
IntegerDataStore	getPositions() Get / compute the positions.
static ArrayDBIDs	topologicalSort(DBIDs oids, DBIDDataStore parent, DoubleDataStore parentDistance) Perform topological sorting based on the successor order.

Methods inherited from class de.lmu.ifi.dbs.elki.result.BasicResult

getLongName, getShortName

Methods inherited from class de.lmu.ifi.dbs.elki.result.AbstractHierarchicalResult

addChildResult, getHierarchy, setHierarchy

Methods inherited from class java.lang.Object

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

Field Detail

ids

DBIDs ids

The DBIDs in this result.

parent

DBIDDataStore parent

The parent DBID relation.

parentDistance

DoubleDataStore parentDistance

Distance to the parent object.

positions

IntegerDataStore positions

Position storage, computed on demand.

Constructor Detail

PointerHierarchyRepresentationResult

public PointerHierarchyRepresentationResult(DBIDs ids,
                                    DBIDDataStore parent,
                                    DoubleDataStore parentDistance)

Constructor.

Parameters:

ids - IDs processed.

parent - Parent pointer.

parentDistance - Distance to parent.

Method Detail

getDBIDs

public DBIDs getDBIDs()

Get the clustered DBIDs.

Returns:

DBIDs

getParentStore

public DBIDDataStore getParentStore()

Get the parent DBID relation.

Returns:

Parent relation.

getParentDistanceStore

public DoubleDataStore getParentDistanceStore()

Get the distance to the parent.

Returns:

Parent distance.

getPositions

public IntegerDataStore getPositions()

Get / compute the positions.

Returns:

Dendrogram positions

topologicalSort

public static ArrayDBIDs topologicalSort(DBIDs oids,
                         DBIDDataStore parent,
                         DoubleDataStore parentDistance)

Perform topological sorting based on the successor order.

Parameters:

oids - IDs to sort

parent - Parent relationship.

parentDistance - Distance to parent.

Returns:

Sorted order