Apriori.java

/***********************************************************************

	This file is part of KEEL-software, the Data Mining tool for regression, 
	classification, clustering, pattern mining and so on.

	Copyright (C) 2004-2010
	
	F. Herrera (herrera@decsai.ugr.es)
    L. S�nchez (luciano@uniovi.es)
    J. Alcal�-Fdez (jalcala@decsai.ugr.es)
    S. Garc�a (sglopez@ujaen.es)
    A. Fern�ndez (alberto.fernandez@ujaen.es)
    J. Luengo (julianlm@decsai.ugr.es)

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program.  If not, see http://www.gnu.org/licenses/
  
**********************************************************************/

package keel.Algorithms.Fuzzy_Rule_Learning.Genetic.IVTURS;

import java.util.*;

/**
 * <p>Title: Apriori</p>
 * <p>Description: This class mines the frecuent fuzzy itemsets and the fuzzy classification associacion rules</p>
 * <p>Copyright: Copyright KEEL (c) 2007</p>
 * <p>Company: KEEL </p>
 * @author Written by Jesus Alcala (University of Granada) 09/02/2011
 * @author Modified by Jose Antonio Sanz (University of Navarra) 19/10/2011
 * @author Modified by Alberto Fernandez (University of Jaen) 24/10/2013
 * @version 1.2
 * @since JDK1.6
 */
public class Apriori {
	ArrayList<Itemset> L2;
	double minsup, minconf;
	double[] minSupps;
	int nClasses, nVariables, depth;
	long ruleStage1;
	RuleBase ruleBase;
	RuleBase ruleBaseClase;
	myDataset train;
	myDataset test;
	DataBase dataBase;

	public Apriori() {
	}

	/**
	 * <p>
	 * Builder
	 * </p>
	 * @param ruleBase Rule base
	 * @param dataBase Data Base
	 * @param train Training dataset
	 * @param minsup Minimum support.
	 * @param minconf Maximum Confidence.
	 * @param depth Depth of the trees (Depthmax)
	 * @return A object Apriori
	 */
	public Apriori(RuleBase ruleBase, DataBase dataBase, myDataset train, myDataset test, double minsup, double minconf, int depth) {
		this.train = train;
		this.test = test;
		this.dataBase = dataBase;
		this.ruleBase = ruleBase;
		this.minconf = minconf;
		this.depth = depth;
		this.nClasses = this.train.getnClasses();
		this.nVariables = this.train.getnInputs();

		this.L2 = new ArrayList<Itemset> ();
		minSupps = new double[this.nClasses];
		for (int i=0; i < this.nClasses; i++)  minSupps[i] = this.train.frecuentClass(i) * minsup;
	}


	public void generateRB () {
		int i, j, uncover;

		ruleStage1 = 0;

		this.ruleBaseClase = new RuleBase(this.dataBase, this.train, this.test, this.ruleBase.getK(), this.ruleBase.getTypeInference());

		for (i=0; i < this.nClasses; i++) {
			this.minsup = minSupps[i]; 
			this.generateL2(i);
			this.generateLarge (this.L2, i);

			this.ruleBaseClase.reduceRules(i);

			this.ruleBase.add(this.ruleBaseClase);
			this.ruleBaseClase.clear();
			System.gc();
		} 
	}

	private void generateL2(int clas) {
		int i, j, k, uncover;
		Item item;
		Itemset itemset;

		this.L2.clear();
		itemset = new Itemset(clas);

		for (i=0; i < this.nVariables; i++) {
			if (this.dataBase.numLabels(i) > 1) {
				for (j=0; j < this.dataBase.numLabels(i); j++) {
					item = new Item(i, j);
					itemset.add(item);
					itemset.calculateSupports(this.dataBase, this.train);
					if (itemset.getSupportClass()[0] >= this.minsup)  this.L2.add(itemset.clone());
					itemset.remove(0);
				}
			}
		}

		this.generateRules(this.L2, clas);
	}


	public int hasUncoverClass(int clas) {
		int uncover;
		double degree[] = new double[2];
		Itemset itemset;
		boolean stop;

		uncover = 0;
		for (int j = 0; j < train.size(); j++) {
			if (this.train.getOutputAsInteger(j) == clas) {
				stop = false;
				for (int i=0; i < L2.size() && !stop; i++) {
					itemset = L2.get(i);
					degree = itemset.degree(this.dataBase, this.train.getExample(j));
					if (degree[0] > 0.0)  stop = true;
				}

				if (!stop)  uncover++;
			}
		}

		return uncover;
	}


	private void generateLarge (ArrayList<Itemset> Lk, int clas) {
		int i, j, size;
		ArrayList<Itemset> Lnew;
		Itemset newItemset, itemseti, itemsetj;

		size = Lk.size();

		if (size > 1) {
			if (((Lk.get(0)).size() < this.nVariables) && ((Lk.get(0)).size() < this.depth)) {
				Lnew = new ArrayList<Itemset> ();

				for (i = 0; i < size-1; i++) {
					itemseti = Lk.get(i);
					for (j = i+1; j < size; j++) {
						itemsetj = Lk.get(j);
						if (this.isCombinable(itemseti, itemsetj)) {
							newItemset = itemseti.clone();
							newItemset.add((itemsetj.get(itemsetj.size()-1)).clone());
							newItemset.calculateSupports(this.dataBase, this.train);
							if (newItemset.getSupportClass()[0] >= this.minsup)  Lnew.add(newItemset);
						}
					}

					this.generateRules(Lnew, clas);
					this.generateLarge(Lnew, clas);
					Lnew.clear();
					System.gc();
				}
			}
		}
	}

	private boolean isCombinable(Itemset itemseti, Itemset itemsetj) {
		int i;
		Item itemi, itemj;
		Itemset itemset;

		itemi = itemseti.get(itemseti.size()-1);
		itemj = itemsetj.get(itemseti.size()-1);
		if (itemi.getVariable() >= itemj.getVariable())  return (false);

		return (true);
	}

	public long getRulesStage1() {
		return (ruleStage1);
	}

	private void generateRules(ArrayList<Itemset> Lk, int clas) {
		int i, uncover;
		Itemset itemset;
		double confidence[] = new double[2];
		double var1[] = new double[2];
		double var2[] = new double[2];

		for (i=Lk.size() - 1; i >= 0; i--) {
			itemset = Lk.get(i);
			var2 = itemset.getSupport();
			if (var2[0] > 0.0){                      var1 = itemset.getSupportClass(); 
			confidence[0] = var1[0] / var2[0];
			confidence[1] = var1[1] / var2[1];
			}
			else{
				confidence[0] = confidence[1] = 0.0;
			}
			if (confidence[0] > 0.4) {
				this.ruleBaseClase.add(itemset);
				ruleStage1++;
			}
			if (confidence[0] > this.minconf)  Lk.remove(i);
		}

		if (this.ruleBaseClase.size() > 500000) {
			this.ruleBaseClase.reduceRules(clas);
			//System.out.println("Number of rules: " + this.ruleBase.size());
			System.gc();
		}
	}
}