Package elki.algorithm.statistics

Class AveragePrecisionAtK<O>

java.lang.Object

elki.algorithm.statistics.AveragePrecisionAtK<O>

Type Parameters:

O - Object type

All Implemented Interfaces:

Algorithm

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

Evaluate a distance functions performance by computing the average precision at k, when ranking the objects by distance.

Since:

0.5.0

Author:

Erich Schubert

Nested Class Summary

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 boolean	includeSelf	Include query object in evaluation.
private int	k	The parameter k - the number of neighbors to retrieve.
private static Logging	LOG	The logger for this class.
private RandomFactory	random	Random sampling seed.
private double	sampling	Relative number of object to use in sampling.

Constructor Summary

Constructors

Constructor	Description
AveragePrecisionAtK(Distance<? super O> distance, int k, double sampling, RandomFactory random, boolean includeSelf)	Constructor.

Method Summary

Modifier and Type	Method	Description
TypeInformation[]	getInputTypeRestriction()	Get the input type restriction used for negotiating the data query.
protected static boolean	match(java.lang.Object ref, java.lang.Object test)	Test whether two relation agree.
CollectionResult<double[]>	run(Relation<O> relation, Relation<?> lrelation)	Run the algorithm

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

The logger for this class.

distance

private Distance<? super O> distance

Distance function used.

k

private int k

The parameter k - the number of neighbors to retrieve.

sampling

private double sampling

Relative number of object to use in sampling.

random

private RandomFactory random

Random sampling seed.

includeSelf

private boolean includeSelf

Include query object in evaluation.

Constructor Detail

AveragePrecisionAtK

public AveragePrecisionAtK(Distance<? super O> distance,
                           int k,
                           double sampling,
                           RandomFactory random,
                           boolean includeSelf)

Constructor.

Parameters:

distance - Distance function

k - K parameter

sampling - Sampling rate

random - Random sampling generator

includeSelf - Include query object in evaluation

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,
                                      Relation<?> lrelation)

Run the algorithm

Parameters:

relation - Relation for distance computations

lrelation - Relation for class label comparison

Returns:

Vectors containing mean and standard deviation.

match

protected static boolean match(java.lang.Object ref,
                               java.lang.Object test)

Test whether two relation agree.

Parameters:

ref - Reference object

test - Test object

Returns:

true if the objects match