de.lmu.ifi.dbs.elki.algorithm.statistics

Class DistanceStatisticsWithClasses<O>

java.lang.Object

de.lmu.ifi.dbs.elki.algorithm.AbstractAlgorithm<R>

de.lmu.ifi.dbs.elki.algorithm.AbstractDistanceBasedAlgorithm<O,CollectionResult<double[]>>

de.lmu.ifi.dbs.elki.algorithm.statistics.DistanceStatisticsWithClasses<O>

Type Parameters:

O - Object type

All Implemented Interfaces:

Algorithm, DistanceBasedAlgorithm<O>

@Title(value="Distance Histogram")
 @Description(value="Computes a histogram over the distances occurring in the data set.")
public class DistanceStatisticsWithClasses<O>
extends AbstractDistanceBasedAlgorithm<O,CollectionResult<double[]>>

Algorithm to gather statistics over the distance distribution in the data set.

Since:

0.2

Author:

Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DistanceStatisticsWithClasses.Parameterizer<O> Parameterization class.

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	exact Compute exactly (slower).
private static Logging	LOG The logger for this class.
protected int	numbin Number of bins to use in sampling.
protected boolean	sampling Sampling flag.

Fields inherited from class de.lmu.ifi.dbs.elki.algorithm.AbstractAlgorithm

ALGORITHM_ID

Fields inherited from interface de.lmu.ifi.dbs.elki.algorithm.DistanceBasedAlgorithm

DISTANCE_FUNCTION_ID

Constructor Summary

Constructors

Constructor and Description
DistanceStatisticsWithClasses(DistanceFunction<? super O> distanceFunction, int numbins, boolean exact, boolean sampling) Constructor.

Method Summary

Modifier and Type	Method and Description
private DoubleMinMax	exactMinMax(Relation<O> relation, DistanceQuery<O> distFunc) Compute the exact maximum and minimum.
TypeInformation[]	getInputTypeRestriction() Get the input type restriction used for negotiating the data query.
protected Logging	getLogger() Get the (STATIC) logger for this class.
HistogramResult	run(Database database) Runs the algorithm.
private DoubleMinMax	sampleMinMax(Relation<O> relation, DistanceQuery<O> distFunc) Estimate minimum and maximum via sampling.
private static void	shrinkHeap(java.util.TreeSet<DoubleDBIDPair> hotset, int k) Shrink the heap of "hot" (extreme) items.

Methods inherited from class de.lmu.ifi.dbs.elki.algorithm.AbstractDistanceBasedAlgorithm

getDistanceFunction

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

The logger for this class.

numbin

protected int numbin

Number of bins to use in sampling.

sampling

protected boolean sampling

Sampling flag.

exact

protected boolean exact

Compute exactly (slower).

Constructor Detail

DistanceStatisticsWithClasses

public DistanceStatisticsWithClasses(DistanceFunction<? super O> distanceFunction,
                                     int numbins,
                                     boolean exact,
                                     boolean sampling)

Constructor.

Parameters:

distanceFunction - Distance function to use

numbins - Number of bins

exact - Exactness flag

sampling - Sampling flag

Method Detail

run

public HistogramResult run(Database database)

Description copied from interface: Algorithm

Runs the algorithm.

Specified by:

run in interface Algorithm

Overrides:

run in class AbstractAlgorithm<CollectionResult<double[]>>

Parameters:

database - the database to run the algorithm on

Returns:

the Result computed by this algorithm

sampleMinMax

private DoubleMinMax sampleMinMax(Relation<O> relation,
                                  DistanceQuery<O> distFunc)

Estimate minimum and maximum via sampling.

Parameters:

relation - Relation to process

distFunc - Distance function to use

Returns:

Minimum and maximum

exactMinMax

private DoubleMinMax exactMinMax(Relation<O> relation,
                                 DistanceQuery<O> distFunc)

Compute the exact maximum and minimum.

Parameters:

relation - Relation to process

distFunc - Distance function

Returns:

Exact maximum and minimum

shrinkHeap

private static void shrinkHeap(java.util.TreeSet<DoubleDBIDPair> hotset,
                               int k)

Shrink the heap of "hot" (extreme) items.

Parameters:

hotset - Set of hot items

k - target size

getInputTypeRestriction

public TypeInformation[] getInputTypeRestriction()

Description copied from class: AbstractAlgorithm

Get the input type restriction used for negotiating the data query.

Specified by:

getInputTypeRestriction in interface Algorithm

Specified by:

getInputTypeRestriction in class AbstractAlgorithm<CollectionResult<double[]>>

Returns:

Type restriction

getLogger

protected Logging getLogger()

Description copied from class: AbstractAlgorithm

Get the (STATIC) logger for this class.

Specified by:

getLogger in class AbstractAlgorithm<CollectionResult<double[]>>

Returns:

the static logger