de.lmu.ifi.dbs.elki.index.preprocessed.snn
Class SharedNearestNeighborPreprocessor<O,D extends Distance<D>>

java.lang.Object
  de.lmu.ifi.dbs.elki.index.AbstractIndex<O>
      de.lmu.ifi.dbs.elki.index.preprocessed.AbstractPreprocessorIndex<O,TreeSetDBIDs>
          de.lmu.ifi.dbs.elki.index.preprocessed.snn.SharedNearestNeighborPreprocessor<O,D>

Type Parameters:

O - the type of database objects the preprocessor can be applied to

D - the type of distance the used distance function will return

All Implemented Interfaces:

Index, SharedNearestNeighborIndex<O>, Result

@Title(value="Shared nearest neighbor Preprocessor")
@Description(value="Computes the k nearest neighbors of objects of a certain database.")
public class SharedNearestNeighborPreprocessor<O,D extends Distance<D>>
extends AbstractPreprocessorIndex<O,TreeSetDBIDs>
implements SharedNearestNeighborIndex<O>

A preprocessor for annotation of the ids of nearest neighbors to each database object.

The k nearest neighbors are assigned based on an arbitrary distance function. This functionality is similar but not identical to MaterializeKNNPreprocessor: While it also computes the k nearest neighbors, it does not keep the actual distances, but organizes the NN set in a TreeSet for fast set operations.

Nested Class Summary

static class

SharedNearestNeighborPreprocessor.Factory<O,D extends Distance<D>> Factory class

Field Summary

protected DistanceFunction<O,D>	distanceFunction Hold the distance function to be used.
private static Logging	logger Get a logger for this class.
protected int	numberOfNeighbors Holds the number of nearest neighbors to be used.

Fields inherited from class de.lmu.ifi.dbs.elki.index.preprocessed.AbstractPreprocessorIndex

storage

Fields inherited from class de.lmu.ifi.dbs.elki.index.AbstractIndex

relation

Constructor Summary

SharedNearestNeighborPreprocessor(Relation<O> relation, int numberOfNeighbors, DistanceFunction<O,D> distanceFunction)
Constructor.

Method Summary

protected Logging	getLogger() Get the classes static logger.
String	getLongName() A "pretty" name for the result, for use in titles, captions and menus.
TreeSetDBIDs	getNearestNeighborSet(DBID objid) Get the precomputed nearest neighbors
int	getNumberOfNeighbors() Get the number of neighbors
String	getShortName() A short name for the result, useful for file names.
protected void	preprocess() Preprocessing step.

Methods inherited from class de.lmu.ifi.dbs.elki.index.AbstractIndex

delete, deleteAll, getPageFileStatistics, insert, insertAll

Methods inherited from class java.lang.Object

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

Methods inherited from interface de.lmu.ifi.dbs.elki.index.Index

delete, deleteAll, getPageFileStatistics, insert, insertAll

Field Detail

logger

private static final Logging logger

Get a logger for this class.

numberOfNeighbors

protected int numberOfNeighbors

Holds the number of nearest neighbors to be used.

distanceFunction

protected DistanceFunction<O,D extends Distance<D>> distanceFunction

Hold the distance function to be used.

Constructor Detail

SharedNearestNeighborPreprocessor

public SharedNearestNeighborPreprocessor(Relation<O> relation,
                                         int numberOfNeighbors,
                                         DistanceFunction<O,D> distanceFunction)

Constructor.

Parameters:

relation - Database to use

numberOfNeighbors - Number of neighbors

distanceFunction - Distance function

Method Detail

preprocess

protected void preprocess()

Preprocessing step.

getNearestNeighborSet

public TreeSetDBIDs getNearestNeighborSet(DBID objid)

Description copied from interface: SharedNearestNeighborIndex

Get the precomputed nearest neighbors

Specified by:

getNearestNeighborSet in interface SharedNearestNeighborIndex<O>

Parameters:

objid - Object ID

Returns:

Neighbor DBIDs

getLogger

protected Logging getLogger()

Description copied from class: AbstractPreprocessorIndex

Get the classes static logger.

Specified by:

getLogger in class AbstractPreprocessorIndex<O,TreeSetDBIDs>

Returns:

Logger

getLongName

public String getLongName()

Description copied from interface: Result

A "pretty" name for the result, for use in titles, captions and menus.

Specified by:

getLongName in interface Result

Specified by:

getLongName in class AbstractIndex<O>

Returns:

result name

getShortName

public String getShortName()

Description copied from interface: Result

A short name for the result, useful for file names.

Specified by:

getShortName in interface Result

Specified by:

getShortName in class AbstractIndex<O>

Returns:

result name

getNumberOfNeighbors

public int getNumberOfNeighbors()

Get the number of neighbors

Specified by:

getNumberOfNeighbors in interface SharedNearestNeighborIndex<O>

Returns:

NN size