Package elki.algorithm.statistics

Class DistanceQuantileSampler<O>

java.lang.Object

elki.algorithm.statistics.DistanceQuantileSampler<O>

Type Parameters:

O - Object type

All Implemented Interfaces:

Algorithm

public class DistanceQuantileSampler<O>
extends java.lang.Object
implements Algorithm

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	Description
static class	DistanceQuantileSampler.Par<O>	Parameterization class

Nested classes/interfaces inherited from interface elki.Algorithm

Algorithm.Utils

Field Summary

Fields

Modifier and Type	Field	Description
private Distance<? super O>	distance	Distance function used.
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.

Constructor Summary

Constructors

Constructor	Description
DistanceQuantileSampler(Distance<? super O> distance, double quantile, double sampling, boolean nozeros, RandomFactory rand)	Constructor.

Method Summary

Modifier and Type	Method	Description
TypeInformation[]	getInputTypeRestriction()	Get the input type restriction used for negotiating the data query.
CollectionResult<double[]>	run(Relation<O> relation)	Run the distance quantile sampler.

Methods inherited from class java.lang.Object

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

Methods inherited from interface elki.Algorithm

autorun

Field Detail

LOG

private static final Logging LOG

Class logger.

PREFIX

private static final java.lang.String PREFIX

Statistics prefix.

distance

private Distance<? super O> distance

Distance function used.

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(Distance<? super O> distance,
                               double quantile,
                               double sampling,
                               boolean nozeros,
                               RandomFactory rand)

Constructor.

Parameters:

distance - Distance function

quantile - Quantile to compute

sampling - Sampling rate

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

rand - Random generator

Method Detail

getInputTypeRestriction

public TypeInformation[] getInputTypeRestriction()

Description copied from interface: Algorithm

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

Specified by:

getInputTypeRestriction in interface Algorithm

Returns:

Type restriction

run

public CollectionResult<double[]> run(Relation<O> relation)

Run the distance quantile sampler.

Parameters:

relation - Data relation

Returns:

Distances sample