AprioriWithComplement Class Reference

A class that implements the Apriori algorithm with "complements". The user passes a binary matrix to the constructor. For each row in the matrix, the constructor adds the complement of the row to the matrix. The computeItemsets() method computes itemsets in this augmented matrix with one constraint: every computed itemset will contain at least one original (non-complemented) row. Since most matrices are sparse (they contain very few ones), the complement rows contain a very large number of ones. There could be a very large number of itemsets containing only complement rows. This constraint prevents the algorithm from computing these itemsets. ! More...

#include <apriori.h>

Inheritance diagram for AprioriWithComplement:

List of all members.

Public Member Functions
	AprioriWithComplement (vector< vector< unsigned int > > &matrix, map< unsigned int, string > &majorNames, map< unsigned int, string > &minorNames)
	Constructor that reads a binary matrix from a file.
virtual	~AprioriWithComplement ()
	Destructor.
virtual void	computeItemsets (const set< unsigned int > *rowsToAvoidInSeed=NULL, const set< unsigned int > *rowsToAvoidCompletely=NULL)
virtual AprioriLatticeEdgeType	computeLatticeEdgeType (const Itemset &itm1, const Itemset &itm2) const
Protected Member Functions
virtual void	_computeAllRows (vector< unsigned int > &allRows) const
virtual unsigned int	_computeRandomRows (const vector< unsigned int > &allRows, vector< unsigned int > &randomRows) const
virtual bool	_isComplementRow (unsigned int index) const
virtual unsigned int	_getOriginalRow (unsigned int index) const

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Detailed Description

A class that implements the Apriori algorithm with "complements". The user passes a binary matrix to the constructor. For each row in the matrix, the constructor adds the complement of the row to the matrix. The computeItemsets() method computes itemsets in this augmented matrix with one constraint: every computed itemset will contain at least one original (non-complemented) row. Since most matrices are sparse (they contain very few ones), the complement rows contain a very large number of ones. There could be a very large number of itemsets containing only complement rows. This constraint prevents the algorithm from computing these itemsets. !

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Constructor & Destructor Documentation

AprioriWithComplement::AprioriWithComplement	(	vector< vector< unsigned int > > &	matrix,
		map< unsigned int, string > &	majorNames,
		map< unsigned int, string > &	minorNames
	)

Constructor that reads a binary matrix from a file.

Create an instance of Apriori from a file. The file must be in the form of a tab delimited matrix with the first row containing the column names. Each row must begin with the row name. The first token of the first row must exist, but can be any value.

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Member Function Documentation

void AprioriWithComplement::computeItemsets	(	const set< unsigned int > *	rowsToAvoidInSeed = NULL,
		const set< unsigned int > *	rowsToAvoidCompletely = NULL
	)		[virtual]

Compute closed itemsets in the data using the Apriori algorithm.

Parameters:

[in]	rowsToAvoidInSeed,a	pointer to a set of rows to avoid when computing single-row itemsets. The method starts by computing itemsets with single rows. If a row is a member of this set, the method will not use that row to compute a single-row itemset. The row may be used later in computing itemsets with more than one row.
[in]	rowsToAvoidCompletely,a	pointer to a set of rows to avoid when computing any itemset, including single-row itemsets.

Note:

Use the Apriori::getItemsets() method to retrieve the itemsets.

Reimplemented from Apriori.

AprioriLatticeEdgeType AprioriWithComplement::computeLatticeEdgeType	(	const Itemset &	itm1,
		const Itemset &	itm2
	)		const [virtual]

Compute the type of the edge between two itemsets.

Parameters:

[in]	itm1,an	instance of Itemset.
[in]	itm2,an	instance of Itemset.

Returns:

LATTICE_NO_EDGE if there is no relationship between the two itemsets, LATTICE_EDGE if itm1's rows contain itm2's rows, and LATTICE_COMPLEMENT_EDGE if itm1's rows contain the complement of itm2's rows.

Reimplemented from Apriori.

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The documentation for this class was generated from the following files:

• /home/poirel/src/c++/biorithm/libapriori/apriori.h
• /home/poirel/src/c++/biorithm/libapriori/apriori.C