splitterbuilderfamily.java

Boosting算法软件包

package jboost.learner;

import java.util.Vector;

import jboost.booster.Booster;
import jboost.controller.Configuration;
import jboost.examples.ExampleDescription;

/**
 * Implements a meta-class for SplitterBuilders of a certain general type,
 * for example decision stumps, linear rules etc.
 * This class is responsible for constructing the SplitterBuilders that
 * correspond to that class and can be used on the current ExampleDescription.
 *
 * @author Nigel Duffy 								
 */
public abstract class SplitterBuilderFamily {
  
  /**
   * Default constructor							
   */
  public SplitterBuilderFamily() {
  }
  
  /**
   * Constructs a Vector of SplitterBuilderFamilys 	
   * Uses StumpSplitterBuilderFamily as the default splitter builders			
   */
  public static Vector factory(Configuration config) {
    Vector tmp=new Vector();
    SplitterBuilderFamily sbf=null;
    
    sbf=new StumpSplitterBuilderFamily(config);
    tmp.add(sbf);
    
    return(tmp);
  }
  
  /**
   * Construct a vector of SplitterBuilders
   * corresponding to the members of this family as they may apply
   * to the given set of attributes. 
   * 
   * @param An ExampleDescription.
   * @param An array of integers listing the AttributeDescrptions
   *	     for the attributes to which this family should be applied.
   * @param A flag determining whether all the specified attributes should be 
   *        handled or whether the default policy should be used to determine
   *        which should be handled.						*/
  public abstract Vector build(ExampleDescription exDesc,int[] attr, boolean usePolicy, 
      Configuration config, Booster booster) throws IncompAttException; 
  
  /**
   * Use the default policy to construct a Vector of SplitterBuilders for all
   * attributes.								*/
  public Vector build(ExampleDescription ed, Configuration config,
      Booster booster) throws IncompAttException { 
    int[] attr=new int[ed.getAttributes().length];
    for(int i=0;i<attr.length;i++) {
      attr[i]=i;
    }
    return(this.build(ed,attr,true,config,booster));
  }
}