Class Eclat
- java.lang.Object
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- elki.itemsetmining.AbstractFrequentItemsetAlgorithm
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- elki.itemsetmining.Eclat
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- All Implemented Interfaces:
Algorithm
@Reference(authors="M. J. Zaki, S. Parthasarathy, M. Ogihara, W. Li", title="New Algorithms for Fast Discovery of Association Rules", booktitle="Proc. 3rd ACM SIGKDD \'97 Int. Conf. on Knowledge Discovery and Data Mining", url="http://www.aaai.org/Library/KDD/1997/kdd97-060.php", bibkey="DBLP:conf/kdd/ZakiPOL97") public class Eclat extends AbstractFrequentItemsetAlgorithm
Eclat is a depth-first discovery algorithm for mining frequent itemsets.Eclat discovers frequent itemsets by first transforming the data into a (sparse) column-oriented form, then performing a depth-first traversal of the prefix lattice, stopping traversal when the minimum support is no longer satisfied.
This implementation is the basic algorithm only, and does not use diffsets. Columns are represented using a sparse representation, which theoretically is beneficial when the density is less than 1/31. This corresponds roughly to a minimum support of 3% for 1-itemsets. When searching for itemsets with a larger minimum support, it may be desirable to use a dense bitset representation instead and/or implement an automatic switching technique!
Performance of this implementation is probably surpassed with a low-level C implementation based on SIMD bitset operations as long as support of an itemset is high, which are not easily accessible in Java.
Reference:
New Algorithms for Fast Discovery of Association Rules
M. J. Zaki, S. Parthasarathy, M. Ogihara, W. Li
Proc. 3rd ACM SIGKDD '97 Int. Conf. on Knowledge Discovery and Data Mining- Since:
- 0.7.0
- Author:
- Erich Schubert
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
Eclat.Par
Parameterization class.-
Nested classes/interfaces inherited from interface elki.Algorithm
Algorithm.Utils
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Constructor Summary
Constructors Constructor Description Eclat(double minsupp, int minlength, int maxlength)
Constructor.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description private DBIDs[]
buildIndex(Relation<BitVector> relation, int dim, int minsupp)
private void
extractItemsets(DBIDs[] idx, int start, int minsupp, java.util.List<Itemset> solution)
private void
extractItemsets(DBIDs iset, DBIDs[] idx, int[] buf, int depth, int start, int minsupp, java.util.List<Itemset> solution)
TypeInformation[]
getInputTypeRestriction()
Get the input type restriction used for negotiating the data query.private DBIDs
mergeJoin(DBIDs first, DBIDs second)
FrequentItemsetsResult
run(Relation<BitVector> relation)
Run the Eclat algorithm-
Methods inherited from class elki.itemsetmining.AbstractFrequentItemsetAlgorithm
autorun, getMinimumSupport
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Field Detail
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LOG
private static final Logging LOG
Class logger.
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STAT
private static final java.lang.String STAT
Prefix for statistics.
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Method Detail
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getInputTypeRestriction
public TypeInformation[] getInputTypeRestriction()
Description copied from interface:Algorithm
Get the input type restriction used for negotiating the data query.- Returns:
- Type restriction
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run
public FrequentItemsetsResult run(Relation<BitVector> relation)
Run the Eclat algorithm- Parameters:
relation
- Bit vector relation- Returns:
- Frequent patterns found
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extractItemsets
private void extractItemsets(DBIDs[] idx, int start, int minsupp, java.util.List<Itemset> solution)
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extractItemsets
private void extractItemsets(DBIDs iset, DBIDs[] idx, int[] buf, int depth, int start, int minsupp, java.util.List<Itemset> solution)
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