weightdescription.java

Boosting算法软件包

package jboost.examples;

import jboost.controller.Configuration;
import jboost.tokenizer.BadAttException;

/**
 * The description for a private weight of each example.
 */
public class WeightDescription extends NumberDescription {

    public static final double MAX_WEIGHT = 1;
  
  WeightDescription(String name, Configuration config) 
  throws ClassNotFoundException {
    super(name,config);
  }

  
  /** 
   *  Reads a RealAttribute as an example weight
   *  If no value is specified, default to 1
   *  If the value is negative, return 0 as the weight.
   *  If the value is greater than 1, return 1.
   * @param weight the string representation of the weight
   * @return Attribute the RealAttribute corresponding to the weight
   */
  public Attribute str2Att(String weight) throws BadAttException {
    double att = 1.0; // initialized because try complains otherwise.    

    if (weight != null) {
      weight= weight.trim(); 
      if (weight.length() != 0) {
        try {
          att= Double.parseDouble(weight);
        } catch (NumberFormatException nfe) {
          throw new BadAttException(weight + " is not a float",0,0);          
        }
        if (att < 0) {
	    att= 0;
	    throw new BadAttException("The weight: " + weight + " is less than 0",0,0);          
        }
        if (att > MAX_WEIGHT) {
	    att= MAX_WEIGHT;
	    throw new BadAttException("The weight: " + weight + " is larger than MAX_WEIGHT=" + MAX_WEIGHT,0,0);          
        } 
      }
    }
    return new RealAttribute (att);
  }

}