ca.pfv.spmf.algorithms.frequentpatterns.charm

Class AlgoCharmMFI

java.lang.Object

ca.pfv.spmf.algorithms.frequentpatterns.charm.AlgoCharmMFI

public class AlgoCharmMFI
extends java.lang.Object

This is an implementation of the CHARM-MFI algorithm (thesis of L. Szathmary, 2006) that is a simple extension that takes the output of CHARM as input and do post-processing to keep only maximal itemsets.

But it was found that the Charm-MFI algorithm is actually incorrect so this implementation was modified to fix the original algorithm and generate the correct result.

Note that this algorithm is not very efficient because the maximal itemsets are generated by post-processing.

Also, note that this version can save the result to a file or keep it into memory if no output path is provided by the user to the runAlgorithm() method.

See Also:

TriangularMatrix, TransactionDatabase, Itemset, Itemsets, HashTable, AlgoCharm_Bitset

Constructor Summary

Constructors

Constructor and Description
AlgoCharmMFI() Default constructor

Method Summary

Modifier and Type	Method and Description
Itemsets	getItemsets() Get the set of maximal itemsets found by Charm-MFI
void	printStats(int transactionCount) Print statistics about the algorithm execution to System.out.
Itemsets	runAlgorithm(java.lang.String output, Itemsets frequentClosed) Run the CHARM-MFI algorithm.

Methods inherited from class java.lang.Object

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

Constructor Detail

AlgoCharmMFI

public AlgoCharmMFI()

Default constructor

Method Detail

runAlgorithm

public Itemsets runAlgorithm(java.lang.String output,
                             Itemsets frequentClosed)
                      throws java.io.IOException

Run the CHARM-MFI algorithm.

Parameters:

output - an output file path or null if the user want to keep the result in memory.

frequentClosed - a set of frequent closed itemsets

Returns:

the set of maximal itemsets (if the user chose to keep the result in memory.

Throws:

java.io.IOException - An exception if an error occurs while writting the output to a file.

printStats

public void printStats(int transactionCount)

Print statistics about the algorithm execution to System.out.

getItemsets

public Itemsets getItemsets()

Get the set of maximal itemsets found by Charm-MFI

Returns:

the set of maximal itemsets