de.lmu.ifi.dbs.elki.evaluation.paircounting
Class PairCountingFMeasure

java.lang.Object
  de.lmu.ifi.dbs.elki.evaluation.paircounting.PairCountingFMeasure

public class PairCountingFMeasure
extends Object

Compare two clustering results using a pair-counting F-Measure. A pair are any two objects that belong to the same cluster. Two clusterings are compared by comparing their pairs; if two clusterings completely agree, they also agree on every pair; even when the clusters and points are ordered differently. An empty clustering will of course have no pairs, the trivial all-in-one clustering of course has n^2 pairs. Therefore neither recall nor precision itself are useful, however their combination -- the F-Measure -- is useful.

Author:

Erich Schubert

Constructor Summary

PairCountingFMeasure()

Method Summary

static <R extends Clustering<M>,M extends Model,S extends Clustering<N>,N extends Model> double	compareClusterings(R result1, S result2) Compare two clustering results.
static <R extends Clustering<M>,M extends Model,S extends Clustering<N>,N extends Model> double	compareClusterings(R result1, S result2, double beta) Compare two clustering results.
private static double	countPairs(PairSortedGeneratorInterface first, PairSortedGeneratorInterface second, double beta) Compare two sets of generated pairs.
static <R extends Clustering<M>,M extends Model> PairSortedGeneratorInterface	getPairGenerator(R clusters) Get a pair generator for the given Clustering

Methods inherited from class java.lang.Object

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

Constructor Detail

PairCountingFMeasure

public PairCountingFMeasure()

Method Detail

getPairGenerator

public static <R extends Clustering<M>,M extends Model> PairSortedGeneratorInterface getPairGenerator(R clusters)

Get a pair generator for the given Clustering

Type Parameters:

R - Clustering result class

M - Model type

Parameters:

clusters - Clustering result

Returns:

Sorted pair generator

compareClusterings

public static <R extends Clustering<M>,M extends Model,S extends Clustering<N>,N extends Model> double compareClusterings(R result1,
                                                                                                                          S result2,
                                                                                                                          double beta)

Compare two clustering results.

Type Parameters:

R - Result type

M - Model type

S - Result type

N - Model type

Parameters:

result1 - first result

result2 - second result

beta - Beta value for the F-Measure

Returns:

Pair counting F-Measure result.

compareClusterings

public static <R extends Clustering<M>,M extends Model,S extends Clustering<N>,N extends Model> double compareClusterings(R result1,
                                                                                                                          S result2)

Compare two clustering results.

Type Parameters:

R - Result type

M - Model type

S - Result type

N - Model type

Parameters:

result1 - first result

result2 - second result

Returns:

Pair counting F-1-Measure result.

countPairs

private static double countPairs(PairSortedGeneratorInterface first,
                                 PairSortedGeneratorInterface second,
                                 double beta)

Compare two sets of generated pairs.

Parameters:

first - first set

second - second set

beta - beta value for F-Measure

Returns:

F-beta-Measure for pairs.