/**
 *   
 *   AgentAcademy - an open source Data Mining framework for
 *   training intelligent agents
 *
 *   Copyright (C)   2001-2003 AA Consortium.
 *
 *   This library is open source software; you can redistribute it 
 *   and/or modify it under the terms of the GNU Lesser General 
 *   Public License as published by the Free Software Foundation;   
 *   either version 2.0 of the License, or (at your option) any later 
 *   version.
 *
 *   This library 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 Lesser General Public
 *   License along with this library; if not, write to the Free 
 *   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, 
 *   MA  02111-1307 USA
 * 
 */

package org.agentacademy.modules.dataminer.classifiers;

/**
 * <p>Title: The Data Miner prototype</p>
 * <p>Description: A prototype for the DataMiner (DM), the Agent Academy (AA) module responsible for performing data mining on the contents of the Agent Use Repository (AUR). The extracted knowledge is to be sent back to the AUR in the form of a PMML document.</p>
 * <p>Copyright: Copyright (c) 2002</p>
 * <p>Company: CERTH</p>
 * @author asymeon
 * @version 0.3
 */

import org.agentacademy.modules.dataminer.core.*;

/**
 * Class implementing a "no-split"-split.
 *
 */
public final class NoSplit extends ClassifierSplitModel{

  /**
   * Creates "no-split"-split for given distribution.
   */
  public NoSplit(Distribution distribution){

    m_distribution = new Distribution(distribution);
    m_numSubsets = 1;
  }

  /**
   * Creates a "no-split"-split for a given set of instances.
   *
   * @exception Exception if split can't be built successfully
   */
  public final void buildClassifier(Instances instances)
       throws Exception {

    m_distribution = new Distribution(instances);
    m_numSubsets = 1;
  }

  /**
   * Always returns 0 because only there is only one subset.
   */
  public final int whichSubset(Instance instance){

    return 0;
  }

  /**
   * Always returns null because there is only one subset.
   */
  public final double [] weights(Instance instance){

    return null;
  }

  /**
   * Does nothing because no condition has to be satisfied.
   */
  public final String leftSide(Instances instances){

    return "";
  }

  /**
   * Does nothing because no condition has to be satisfied.
   */
  public final String rightSide(int index, Instances instances){

    return "";
  }

  /**
   * Returns a string containing java source code equivalent to the test
   * made at this node. The instance being tested is called "i".
   *
   * @param index index of the nominal value tested
   * @param data the data containing instance structure info
   * @return a value of type 'String'
   */
  public final String sourceExpression(int index, Instances data) {

    return "true";  // or should this be false??
  }

}