mutablecontext.java

最大熵分类器

///////////////////////////////////////////////////////////////////////////////
//Copyright (C) 2005 Thomas Morton
//
// This library is free 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 2.1 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 program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
//////////////////////////////////////////////////////////////////////////////   
package opennlp.maxent;

import java.util.Arrays;

/**
 * Class used to store parameters or expected values associated with this context which
 * can be updated or assigned. 
 * @author Tom Morton
 *
 */
public class MutableContext extends Context {

  /**
   * Creates a new parametes object with the specifed parameters associated with the specified
   * outcome pattern.
   * @param outcomePattern Array of outcomes for which parameters exists for this context.
   * @param parameters Paramaters for the outcomes specified.
   */
  public MutableContext(int[] outcomePattern, double[] parameters) {
    super(outcomePattern, parameters);
  }
  
  /**
   * Assigns the parameter or expected value at the specified outcomeIndex the specified value. 
   * @param outcomeIndex The index of the parameter or expected value to be updated. 
   * @param value The value to be assigned.
   */
  public void setParameter(int outcomeIndex, double value) {
    parameters[outcomeIndex]=value;
  }
  
  /**
   * Updated the parameter or expected value at the specified outcomeIndex by adding the specified value to its current value.
   * @param outcomeIndex The index of the parameter or expected value to be updated.
   * @param value The value to be added.
   */
  public void updateParameter(int outcomeIndex, double value) {
    parameters[outcomeIndex]+=value;
  }
  
  public boolean contains(int outcome) {
    return(Arrays.binarySearch(outcomes,outcome) >= 0);
  }
}