Sampling.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/
  
**********************************************************************/

/**
 * <p>
 * @author Written by Jaume Bacardit (La Salle, Ram�n Llull University - Barcelona) 28/03/2004
 * @author Modified by Xavi Sol� (La Salle, Ram�n Llull University - Barcelona) 23/12/2008
 * @version 1.1
 * @since JDK1.2
 * </p>
 */


package keel.Algorithms.Genetic_Rule_Learning.GAssist;

import keel.Algorithms.Genetic_Rule_Learning.Globals.*;

public class Sampling {
/**
 * <p>
 * Helps managing a sampling without replacement process
 * </p>
 */
	
	
  int maxSize;
  int num;
  int[] sample;

  void initSampling() {
    for (int i = 0; i < maxSize; i++) {
      sample[i] = i;
    }
    num = maxSize;
  }

  public Sampling(int _maxSize) {
    maxSize = _maxSize;
    sample = new int[maxSize];
    initSampling();
  }

  public int numSamplesLeft() {
    return num;
  }

  public int getSample() {
    int pos = Rand.getInteger(0, num - 1);
    int value = sample[pos];
    sample[pos] = sample[num - 1];
    num--;

    if (num == 0) {
      initSampling();
    }

    return value;
  }
}