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

Class DistanceQuantileSampler<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.DistanceQuantileSampler<O>

Type Parameters:

O - Object type

All Implemented Interfaces:

Algorithm, DistanceBasedAlgorithm<O>

public class DistanceQuantileSampler<O>
extends AbstractDistanceBasedAlgorithm<O,CollectionResult<double[]>>

Compute a quantile of a distance sample, useful for choosing parameters for algorithms. TODO: allow specifying multiple quantiles.

Since:

0.7.0

Author:

Erich Schubert

Nested Class Summary

Nested Classes

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

Field Summary

Fields

Modifier and Type	Field and Description
private static Logging	LOG Class logger.
private boolean	nozeros Flag to ignore zero distances (recommended with many duplicates).
private static java.lang.String	PREFIX Statistics prefix.
private double	quantile Quantile to compute.
private RandomFactory	rand Random generator.
private double	sampling Sampling rate.

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
DistanceQuantileSampler(DistanceFunction<? super O> distanceFunction, double quantile, double sampling, boolean nozeros, RandomFactory rand) Constructor.

Method Summary

Modifier and Type	Method and Description
TypeInformation[]	getInputTypeRestriction() Get the input type restriction used for negotiating the data query.
protected Logging	getLogger() Get the (STATIC) logger for this class.
CollectionResult<double[]>	run(Database database, Relation<O> rel) Run the distance quantile sampler.

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

getDistanceFunction

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

run

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.algorithm.Algorithm

run

Field Detail

LOG

private static final Logging LOG

Class logger.

PREFIX

private static final java.lang.String PREFIX

Statistics prefix.

quantile

private double quantile

Quantile to compute.

sampling

private double sampling

Sampling rate.

nozeros

private boolean nozeros

Flag to ignore zero distances (recommended with many duplicates).

rand

private RandomFactory rand

Random generator.

Constructor Detail

DistanceQuantileSampler

public DistanceQuantileSampler(DistanceFunction<? super O> distanceFunction,
                               double quantile,
                               double sampling,
                               boolean nozeros,
                               RandomFactory rand)

Constructor.

Parameters:

distanceFunction - Distance function

quantile - Quantile to compute

sampling - Sampling rate

nozeros - Flag to ignore zero distances (recommended with many duplicates)

rand - Random generator

Method Detail

run

public CollectionResult<double[]> run(Database database,
                                      Relation<O> rel)

Run the distance quantile sampler.

Parameters:

database -

rel -

Returns:

Distances sample

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