org.simmetrics.metrics

Class GeneralizedOverlapCoefficient<T>

java.lang.Object

org.simmetrics.metrics.GeneralizedOverlapCoefficient<T>

Type Parameters:

T - type of the token

All Implemented Interfaces:

Metric<com.google.common.collect.Multiset<T>>, MultisetMetric<T>

public final class GeneralizedOverlapCoefficient<T>
extends Object
implements MultisetMetric<T>

The generalized overlap coefficient measures the overlap between two multisets. The similarity is defined as the size of the intersection divided by the smaller of the size of the two sets

similarity(q,r) = ∣q ∩ r∣ / min{∣q∣, ∣r∣}

Unlike the overlap coefficient the occurrence (cardinality) of an entry is taken into account. E.g. [hello, world] and [hello, world, hello, world] would be identical when compared with the overlap coefficient index but are dissimilar when the generalized version is used.

This class is immutable and thread-safe.

See Also:

OverlapCoefficient, Wikipedia - Overlap Coefficient

Constructor Summary

Constructors

Constructor and Description
GeneralizedOverlapCoefficient()

Method Summary

Modifier and Type	Method and Description
float	compare(com.google.common.collect.Multiset<T> a, com.google.common.collect.Multiset<T> b) Measures the similarity between multisets a and b.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

GeneralizedOverlapCoefficient

public GeneralizedOverlapCoefficient()

Method Detail

compare

public float compare(com.google.common.collect.Multiset<T> a,
                     com.google.common.collect.Multiset<T> b)

Description copied from interface: MultisetMetric

Measures the similarity between multisets a and b. The measurement results in a value between 0 and 1 inclusive. A value of zero indicates that the sets are dissimilar, a value of 1 indicates they are similar.

Results are undefined if a and b are based on different equivalence relations (as HashMultiset and TreeMultiset are).

Specified by:

compare in interface Metric<com.google.common.collect.Multiset<T>>

Specified by:

compare in interface MultisetMetric<T>

Parameters:

a - multisets a to compare

b - multisets b to compare

Returns:

a value between 0 and 1 inclusive indicating similarity

toString

public String toString()

Overrides:

toString in class Object