Logo
Distributed Genetic Programming Framework
print print

File org.dgpf.search.algorithms.ga.selection.RouletteWheelSelection.java

Here you can find all the information about the file org.dgpf.search.algorithms.ga.selection.RouletteWheelSelection.java. You may explore it here or download it onto your local disk.
/*
 * Copyright (c) 2006 Thomas Weise
 * 
 * E-Mail           : tweise@gmx.de
 * Creation Date    : 2006-05-28 09:23:35
 * Original Filename: org.dgpf.search.algorithms.ga.selection.RouletteWheelSelection.java
 * Version          : 1.0.1
 * Last modification: 2006-05-31
 *                by: Thomas Weise
 * 
 * License          : GNU LESSER GENERAL PUBLIC LICENSE
 *                    Version 2.1, February 1999
 *                    You should have received a copy of this license along
 *                    with this library; if not, write to the Free Software
 *                    Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 *                    MA 02111-1307, USA or download the license under
 *                    http://www.gnu.org/copyleft/lesser.html.
 *                    
 * Warranty         : This software is provided "as is" without any
 *                    warranty; without even the implied warranty of
 *                    merchantability or fitness for a particular purpose.
 *                    See the Gnu Lesser General Public License for more
 *                    details.
 */

 
package org.dgpf.search.algorithms.ga.selection;

import java.io.Serializable;

import org.dgpf.search.algorithms.ga.SelectionAlgorithm;
import org.dgpf.search.algorithms.ga.sorting.ScalarSorting;
import org.dgpf.search.api.Individual;
import org.sfc.math.stochastic.Randomizer;

/**
 * The roulette wheel selection algorithm is a commonly known appreciated
 * technique for selection.
 * Find more information at
 * <a href="http://en.wikipedia.org/wiki/Fitness_proportionate_selection">http://en.wikipedia.org/wiki/Fitness_proportionate_selection</a>. 
 *
 * @author Thomas Weise
 */

public final  class RouletteWheelSelection extends SelectionAlgorithm
  {
/**
 * The serial version uid.
 */

  private   static  final long    serialVersionUID        = 1;

/**
 * The roulette wheel selection instance.
 */

  public  static  final SelectionAlgorithm INSTANCE
      = new RouletteWheelSelection();
  
/**
 * Create a new instance of roulette wheel selection.
 */

  private RouletteWheelSelection()
    {
    super(new ScalarSorting());
    }
  

/**
 * Select one individual out of the population for reproduction (crossover
 * or mutation). The individuals in the array are ordered by the search's
 * current comparator, with the fittest individual at index <code>0</code>
 * and the worst at index <code>p_count-1</code>.
 * @param p_random        The randomizer to be used for the selection.
 * @param p_individuals   The population of individuals after being
 *                        preprocessed.
 * @param p_count         The count of valid items inside the population
 *                        array.
 * @param <Genotype>      The genotype of the individuals to select.
 * @return  An individual to reproduce.
 */

  @Override
  public  final  <Genotype extends Serializable> Individual<Genotype>
                         select(final Randomizer             p_random,
                                final Individual<Genotype>[] p_individuals,
                                final int                    p_count)
    {
    return p_individuals[((ScalarSorting)(this.get_sorting_algorithm()))
                          .get_norm_index(p_random.nextDouble(), p_count)];
    }
  

/**
 * Check whether this object equals another one. This method is internally
 * invoked by <code>equals()</code>. 
 * @param p_object  The object to compare with.
 * @return <code>true</code> if and only if this object equals to the other
 *         one.
 */

  @Override
  protected final boolean is_equal  (final Object p_object)
    {
    return (p_object instanceof RouletteWheelSelection);
    }
  }

File Information:

file name:RouletteWheelSelection.java
package:org.dgpf.search.algorithms.ga.selection
qualified name:org.dgpf.search.algorithms.ga.selection.RouletteWheelSelection.java
file type:Java Source File
download location:download http://dgpf.sourceforge.net/source/org/dgpf/search/algorithms/ga/selection/RouletteWheelSelection.java
size:3.726 KB (3816 B)
uploaded: 2015-07-22 04:10:59 GMT+0000
last update: 2006-08-22 13:05:50 GMT+0000
last access: 2017-11-18 21:27:16 GMT+0000

statistics online since 2006-01-02.   RSS Feed
Contact us by sending an email to tweise@gmx.de to receive further information, to report errors, or to join our project.
All content on this site (http://dgpf.sourceforge.net/) is LGPL-licensed.
http://dgpf.sourceforge.net/scripts/source/source.php last modified at 2015-07-22 04:10:53 GMT+0000 served at 2017-11-18 21:27:16 GMT+0000.
Valid CSS Valid XHTML 1.1
Valid RSS SourceForge.net Logo