asevaluation.java

一个数据挖掘系统的源码

/**
 *   
 *   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.attributeSelection;

import java.io.Serializable;

import org.agentacademy.modules.dataminer.core.Instances;
import org.agentacademy.modules.dataminer.core.SerializedObject;
import org.agentacademy.modules.dataminer.core.Utils;


public abstract class ASEvaluation implements Serializable {

  // ===============
  // Public methods.
  // ===============

  /**
   * Generates a attribute evaluator. Has to initialize all fields of the
   * evaluator that are not being set via options.
   *
   * @param data set of instances serving as training data
   * @exception Exception if the evaluator has not been
   * generated successfully
   */
  public abstract void buildEvaluator(Instances data) throws Exception;

  /**
   * Provides a chance for a attribute evaluator to do any special
   * post processing of the selected attribute set.
   *
   * @param attributeSet the set of attributes found by the search
   * @return a possibly ranked list of postprocessed attributes
   * @exception Exception if postprocessing fails for some reason
   */
  public int [] postProcess(int [] attributeSet)
    throws Exception
  {
    return attributeSet;
  }

  /**
   * Creates a new instance of an attribute/subset evaluator
   * given it's class name and
   * (optional) arguments to pass to it's setOptions method. If the
   * evaluator implements OptionHandler and the options parameter is
   * non-null, the evaluator will have it's options set.
   *
   * @param evaluatorName the fully qualified class name of the evaluator
   * @param options an array of options suitable for passing to setOptions. May
   * be null.
   * @return the newly created evaluator, ready for use.
   * @exception Exception if the evaluator name is invalid, or the options
   * supplied are not acceptable to the evaluator
   */
  public static ASEvaluation forName(String evaluatorName,
				     String [] options) throws Exception
  {
    return (ASEvaluation)Utils.forName(ASEvaluation.class,
				       evaluatorName,
				       options);
  }

  /**
   * Creates copies of the current evaluator. Note that this method
   * now uses Serialization to perform a deep copy, so the evaluator
   * object must be fully Serializable. Any currently built model will
   * now be copied as well.
   *
   * @param model an example evaluator to copy
   * @param num the number of evaluator copies to create.
   * @return an array of evaluators.
   * @exception Exception if an error occurs
   */
  public static ASEvaluation [] makeCopies(ASEvaluation model,
					 int num) throws Exception {

    if (model == null) {
      throw new Exception("No model evaluator set");
    }
    ASEvaluation [] evaluators = new ASEvaluation [num];
    SerializedObject so = new SerializedObject(model);
    for(int i = 0; i < evaluators.length; i++) {
      evaluators[i] = (ASEvaluation) so.getObject();
    }
    return evaluators;
  }
}