stumpsplitterbuilderfamily.java

来自「Boosting算法软件包」· Java 代码 · 共 79 行

package jboost.learner;

import java.util.Vector;
import jboost.booster.Booster;
import jboost.controller.Configuration;
import jboost.examples.AttributeDescription;
import jboost.examples.DiscreteAttribute;
import jboost.examples.ExampleDescription;
import jboost.examples.RealAttribute;
import jboost.examples.SetAttribute;
import jboost.monitor.Monitor;

/**
 * Implements a meta-class for SplitterBuilders of decision stumps.
 * This class is responsible for constructing the SplitterBuilders that
 * correspond to decision stumps and can be used on the current ExampleDescription.
 *
 * @author Nigel Duffy 		
 */
public class StumpSplitterBuilderFamily extends SplitterBuilderFamily {
  private boolean textAbstain;
  private static final String prefix = "learner_";
  
  /**
   * Default constructor							
   */
  public StumpSplitterBuilderFamily(Configuration config) {
    textAbstain = config.getBool(prefix + "textAbstain", false);
    if (Monitor.logLevel>3) {
      Monitor.log("textAbstain = " + textAbstain);
    }
  }
  
  /** 
   * Constructs a vector of single-attribute SplitterBuilders to
   *  match the given ExampleDescription. 	
   */
  public Vector build(ExampleDescription exDesc,int[] attr, boolean usePolicy, 
                      Configuration config, Booster booster) 
  throws IncompAttException {
    // attribute class templates
    RealAttribute realAttribute=new RealAttribute(0.0);
    DiscreteAttribute discreteAttribute=new DiscreteAttribute(0);
    SetAttribute setAttribute=new SetAttribute();
    
    Vector retval=new Vector();
    AttributeDescription[] attrDesc=exDesc.getAttributes();
    int noOfAtt= attr.length;
    SplitterBuilder tmpSB= null;
    
    // check each attribute to make sure that we are ignoring attributes when necessary
    for(int i=0; i < noOfAtt; i++) {
      if (!attrDesc[attr[i]].isIgnored()) {
        Class attributeClass= attrDesc[attr[i]].getAttributeClass();
        
        if (attributeClass.equals(realAttribute.getClass())) {
          tmpSB= new InequalitySplitterBuilder(attr[i], booster,
              new AttributeDescription[] {attrDesc[attr[i]]});
        } else if (attributeClass.equals(discreteAttribute.getClass())) {
          tmpSB= new EqualitySplitterBuilder(attr[i], booster,
              new AttributeDescription[] {attrDesc[attr[i]]});
        } else if (attributeClass.equals(setAttribute.getClass())) {
          tmpSB= SetSplitterBuilder.newSplitterBuilder(attr[i], booster, textAbstain,
              new AttributeDescription[] {attrDesc[attr[i]]});
        } else { 
          throw new IncompAttException("Trying to build SplitterBuilders vector but cannot identify attribute:",attr[i],attributeClass);
        }
        
        if (Monitor.logLevel>3) {
          Monitor.log("attribute " + attr[i] + " class is:" + attributeClass);
        }
        
        retval.add(tmpSB);
      }
    }
  return retval;
  }
}