ca.pfv.spmf.algorithms.frequentpatterns.aprioriTID

Class AlgoAprioriTID

java.lang.Object

ca.pfv.spmf.algorithms.frequentpatterns.aprioriTID.AlgoAprioriTID

public class AlgoAprioriTID
extends java.lang.Object

This is an implementation of the AprioriTID algorithm.

The AprioriTID algorithm finds all the frequents itemsets and their support in a binary context.

AprioriTID can be faster than Apriori and produce the same result.

AprioriTID was originally proposed in :

Agrawal R, Srikant R. "Fast Algorithms for Mining Association Rules", VLDB. Sep 12-15 1994, Chile, 487-99,

This implementation can save the result to a file or keep it into memory if no output path is provided to the runAlgorithm() method.

See Also:

Itemset, Itemsets

Constructor Summary

Constructors

Constructor and Description
AlgoAprioriTID() Default constructor

Method Summary

Modifier and Type	Method and Description
int	getDatabaseSize() Get the number of transactions in the last database read.
void	printStats() Print statistics about the algorithm execution to System.out.
Itemsets	runAlgorithm(java.lang.String input, java.lang.String output, double minsup) This method run the algorithm.
Itemsets	runAlgorithm(TransactionDatabase database, double minsup) This method run the algorithm on a transaction database already in memory.
void	setEmptySetIsRequired(boolean emptySetIsRequired) Method to indicate if the empty set should be included in results or not.
void	setMaxItemsetSize(int maxItemsetSize) Set the maximum itemset size of itemsets to be found

Methods inherited from class java.lang.Object

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

Constructor Detail

AlgoAprioriTID

public AlgoAprioriTID()

Default constructor

Method Detail

runAlgorithm

public Itemsets runAlgorithm(TransactionDatabase database,
                             double minsup)
                      throws java.lang.NumberFormatException,
                             java.io.IOException

This method run the algorithm on a transaction database already in memory.

Parameters:

database - the transaction database

minsup - the minimum support threshold as a percentage (double)

Returns:

the method returns frequent itemsets

Throws:

java.io.IOException - exception if error reading/writing the file

java.lang.NumberFormatException

runAlgorithm

public Itemsets runAlgorithm(java.lang.String input,
                             java.lang.String output,
                             double minsup)
                      throws java.lang.NumberFormatException,
                             java.io.IOException

This method run the algorithm.

Parameters:

input - the file path of an input file. if null, the result is returned by the method.

output - the output file path

minsup - the minimum support threshold as a percentage (double)

Returns:

if no output file path is provided, the method return frequent itemsets, otherwise null

Throws:

java.io.IOException - exception if error reading/writing the file

java.lang.NumberFormatException

setMaxItemsetSize

public void setMaxItemsetSize(int maxItemsetSize)

Set the maximum itemset size of itemsets to be found

Parameters:

maxItemsetSize - maximum itemset size.

setEmptySetIsRequired

public void setEmptySetIsRequired(boolean emptySetIsRequired)

Method to indicate if the empty set should be included in results or not.

Parameters:

emptySetIsRequired - if true the empty set will be included.

printStats

public void printStats()

Print statistics about the algorithm execution to System.out.

getDatabaseSize

public int getDatabaseSize()

Get the number of transactions in the last database read.

Returns:

number of transactions.