Package org.apache.commons.collections4.bloomfilter

Class SetOperations

java.lang.Object

org.apache.commons.collections4.bloomfilter.SetOperations

public final class SetOperations
extends java.lang.Object

Implementations of set operations on BitMapExtractors.

Since:

4.5.0-M1

Method Summary

Modifier and Type	Method	Description
static int	andCardinality(BitMapExtractor first, BitMapExtractor second)	Calculates the cardinality of the logical AND of the bit maps for the two filters.
static int	cardinality(BitMapExtractor bitMapExtractor)	Calculates the cardinality of a BitMapExtractor.
static double	cosineDistance(BitMapExtractor first, BitMapExtractor second)	Calculates the Cosine distance between two BitMapExtractor.
static double	cosineSimilarity(BitMapExtractor first, BitMapExtractor second)	Calculates the Cosine similarity between two BitMapExtractors.
static double	cosineSimilarity(BloomFilter<?> first, BloomFilter<?> second)	Calculates the Cosine similarity between two Bloom filters.
static int	hammingDistance(BitMapExtractor first, BitMapExtractor second)	Calculates the Hamming distance between two BitMapExtractors.
static double	jaccardDistance(BitMapExtractor first, BitMapExtractor second)	Calculates the Jaccard distance between two BitMapExtractor.
static double	jaccardSimilarity(BitMapExtractor first, BitMapExtractor second)	Calculates the Jaccard similarity between two BitMapExtractor.
static int	orCardinality(BitMapExtractor first, BitMapExtractor second)	Calculates the cardinality of the logical OR of the bit maps for the two filters.
static int	xorCardinality(BitMapExtractor first, BitMapExtractor second)	Calculates the cardinality of the logical XOR of the bit maps for the two filters.

Methods inherited from class java.lang.Object

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

Method Detail

andCardinality

public static int andCardinality(BitMapExtractor first,
                                 BitMapExtractor second)

Calculates the cardinality of the logical AND of the bit maps for the two filters.

Parameters:

first - the first BitMapExtractor.

second - the second BitMapExtractor

Returns:

the cardinality of the AND of the filters.

cardinality

public static int cardinality(BitMapExtractor bitMapExtractor)

Calculates the cardinality of a BitMapExtractor. By necessity this method will visit each bit map created by the bitMapExtractor.

Parameters:

bitMapExtractor - the extractor to calculate the cardinality for.

Returns:

the cardinality of the bit maps produced by the bitMapExtractor.

cosineDistance

public static double cosineDistance(BitMapExtractor first,
                                    BitMapExtractor second)

Calculates the Cosine distance between two BitMapExtractor.

Cosine distance is defined as 1 - Cosine similarity

Parameters:

first - the first BitMapExtractor.

second - the second BitMapExtractor.

Returns:

the jaccard distance.

cosineSimilarity

public static double cosineSimilarity(BitMapExtractor first,
                                      BitMapExtractor second)

Calculates the Cosine similarity between two BitMapExtractors.

Also known as Orchini similarity and the Tucker coefficient of congruence or Ochiai similarity.

If either extractor is empty the result is 0 (zero)

Parameters:

first - the first BitMapExtractor.

second - the second BitMapExtractor.

Returns:

the Cosine similarity.

cosineSimilarity

public static double cosineSimilarity(BloomFilter<?> first,
                                      BloomFilter<?> second)

Calculates the Cosine similarity between two Bloom filters.

Also known as Orchini similarity and the Tucker coefficient of congruence or Ochiai similarity.

If either filter is empty (no enabled bits) the result is 0 (zero)

This is a version of cosineSimilarity optimized for Bloom filters.

Parameters:

first - the first Bloom filter.

second - the second Bloom filter.

Returns:

the Cosine similarity.

hammingDistance

public static int hammingDistance(BitMapExtractor first,
                                  BitMapExtractor second)

Calculates the Hamming distance between two BitMapExtractors.

Parameters:

first - the first BitMapExtractor.

second - the second BitMapExtractor.

Returns:

the Hamming distance.

jaccardDistance

public static double jaccardDistance(BitMapExtractor first,
                                     BitMapExtractor second)

Calculates the Jaccard distance between two BitMapExtractor.

Jaccard distance is defined as 1 - Jaccard similarity

Parameters:

first - the first BitMapExtractor.

second - the second BitMapExtractor.

Returns:

the Jaccard distance.

jaccardSimilarity

public static double jaccardSimilarity(BitMapExtractor first,
                                       BitMapExtractor second)

Calculates the Jaccard similarity between two BitMapExtractor.

Also known as Jaccard index, Intersection over Union, and Jaccard similarity coefficient

Parameters:

first - the first BitMapExtractor.

second - the second BitMapExtractor.

Returns:

the Jaccard similarity.

orCardinality

public static int orCardinality(BitMapExtractor first,
                                BitMapExtractor second)

Calculates the cardinality of the logical OR of the bit maps for the two filters.

Parameters:

first - the first BitMapExtractor.

second - the second BitMapExtractor

Returns:

the cardinality of the OR of the filters.

xorCardinality

public static int xorCardinality(BitMapExtractor first,
                                 BitMapExtractor second)

Calculates the cardinality of the logical XOR of the bit maps for the two filters.

Parameters:

first - the first BitMapExtractor.

second - the second BitMapExtractor

Returns:

the cardinality of the XOR of the filters.