net.sf.tweety.machinelearning.assoc

Class AprioriMiner<T>

java.lang.Object

net.sf.tweety.machinelearning.assoc.AbstractAssociationRuleMiner<T>

net.sf.tweety.machinelearning.assoc.AprioriMiner<T>

Type Parameters:

T - the type of items

All Implemented Interfaces:

AssociationRuleMiner<T>

public class AprioriMiner<T>
extends AbstractAssociationRuleMiner<T>

Implements the classical Apriori algorithm for association rule mining, cf. [R. Agrawal, R. Srikant. Fast algorithms for mining association rules in large databases. VLDB 1994.]

Author:

Matthias Thimm

Field Summary

Fields

Modifier and Type	Field and Description
private double	minconf the minimum support for mined rules.
private double	minsupport the minimum confidence for mined rules.

Constructor Summary

Constructors

Constructor and Description
AprioriMiner(double minsupport, double minconf) Creates a new Apriori miner with the given minimum support and minimum confidence values.

Method Summary

Modifier and Type	Method and Description
private boolean	checkSubsetCondition(java.util.Collection<T> set, java.util.Collection<java.util.Collection<T>> sets) Checks whether all subsets of set obtained by removing exactly one element, are contained in the given sets.
private java.util.Collection<java.util.Collection<T>>	mineFrequentSets(java.util.Collection<java.util.Collection<T>> database, int maxsize) Extracts all sets of items from database with support at least minsupport.
java.util.Collection<AssociationRule<T>>	mineRules(java.util.Collection<java.util.Collection<T>> database, int conclusion_limit, int total_limit) Mines a set of association rules from the given database.
private java.util.Collection<java.util.Collection<T>>	nextLevel(java.util.Collection<java.util.Collection<T>> lastLevel, int cardinality) Generates all sets of cardinality cardinality s.t.

Methods inherited from class net.sf.tweety.machinelearning.assoc.AbstractAssociationRuleMiner

mineRules, mineRules

Methods inherited from class java.lang.Object

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

Field Detail

minsupport

private double minsupport

the minimum confidence for mined rules.

minconf

private double minconf

the minimum support for mined rules.

Constructor Detail

AprioriMiner

public AprioriMiner(double minsupport,
                    double minconf)

Creates a new Apriori miner with the given minimum support and minimum confidence values.

Parameters:

minsupport - the minimum confidence for mined rules.

minconf - the minimum support for mined rules.

Method Detail

mineRules

public java.util.Collection<AssociationRule<T>> mineRules(java.util.Collection<java.util.Collection<T>> database,
                                                          int conclusion_limit,
                                                          int total_limit)

Description copied from interface: AssociationRuleMiner

Mines a set of association rules from the given database. Only those rules are mined where the conclusion and in total has the maximal given number of elements, respectively.

Parameters:

database - some database

Returns:

a set of association rules.

mineFrequentSets

private java.util.Collection<java.util.Collection<T>> mineFrequentSets(java.util.Collection<java.util.Collection<T>> database,
                                                                       int maxsize)

Extracts all sets of items from database with support at least minsupport.

Parameters:

database - some database

maxsize - the maximal size of mined item sets

Returns:

all sets of items from database with support at least minsupport.

nextLevel

private java.util.Collection<java.util.Collection<T>> nextLevel(java.util.Collection<java.util.Collection<T>> lastLevel,
                                                                int cardinality)

Generates all sets of cardinality cardinality s.t. all subsets of cardinality cardinality-1 are contained in the given set lastLevel.

Parameters:

lastLevel - a set of sets of the same cardinality cardinality

cardinality - the cardinality of all sets in lastLevel

Returns:

all sets of cardinality cardinality s.t. all subsets of cardinality cardinality-1 are contained in the given set lastLevel.

checkSubsetCondition

private boolean checkSubsetCondition(java.util.Collection<T> set,
                                     java.util.Collection<java.util.Collection<T>> sets)

Checks whether all subsets of set obtained by removing exactly one element, are contained in the given sets.

Parameters:

set - some set

sets - a set of sets

Returns:

"true" iff all subsets of set obtained by removing exactly one element, are contained in the given sets.