exampledescription.java

Boosting算法软件包

package jboost.examples;

import java.util.Vector;

/**
 * A description of the fields in a single example
 * @author Yoav Freund
 * @version $Header: /cvsroot/jboost/jboost/src/jboost/examples/ExampleDescription.java,v 1.2 2007/10/02 20:34:56 aarvey Exp $
 */
public class ExampleDescription {
  
  /** An AttributeDescription for the labels */
  private LabelDescription label;
  
  /** An AttributeDescription for the example weights */
  private WeightDescription weight;
  
  /** a description of each attribute */
  private Vector attribute;
  
  /** the index of the example attribute that contains the label */
  private int m_labelIndex;
  
  /** the index of the example attribute that contains the weight */
  private int m_weightIndex;
  
  /** Flag for using private sampling weights */
  private boolean m_useSamplingWeights;

  


  /** 
   * Defaul constructor 								
   */
  public ExampleDescription() {
    attribute=new Vector();
    label= null;
    weight= null;
    m_useSamplingWeights= false;
    m_labelIndex= -1;
    m_weightIndex= -1;
  }
  
  /**
   *  Sets the label description.						
   */
  public void setLabel(AttributeDescription ad) {
    label=(LabelDescription) ad;
  }
  
  /**
   *  Sets the label description.           
   */
  public void setLabel(AttributeDescription ad, int index) {
    label=(LabelDescription) ad;
    m_labelIndex= index;
  }
  
  /**
   * Return the index of the label attribute
   */
  public int getLabelIndex() {
    return m_labelIndex;
  }
  
  /**
   * Return the index of the weight attribute
   */
  public int getWeightIndex() {
    return m_weightIndex;
  }
  
  /** 
   * Assign the weight description 
   */
  public void setWeight(AttributeDescription weightDescription) {
    weight= (WeightDescription) weightDescription;
  }

  /** 
   * Assign the weight description 
   */
  public void setWeight(AttributeDescription weightDescription, int index) {
    weight= (WeightDescription) weightDescription;
    m_weightIndex= index;
  }
  
  /** 
   * Return the WeightDescription
   */
  public WeightDescription getWeightDescription() {
    return weight;
  }
  
  /**
   * If true, then the examples with this description will contain
   * an attribute that measures the example's sampling probability.
   * @param flag
   */
  public void setSamplingWeightsFlag(boolean flag) {
    m_useSamplingWeights= flag;
  }
  
  /**
   * Return the flag value 
   * @param flag
   */
  public boolean getSamplingWeightsFlag() {
    return m_useSamplingWeights;
  }
  
  /** Add an attribute description.						*/
  public void addAttribute(AttributeDescription ad) {
    attribute.add(ad);
  }
  
  /** Converts an Example to a string
   *  this function is here since the way in which examples
   *  are stored needs to use the example description to 
   *  reproduce something interpretable.  					*/
  public String toString(Example e) throws Exception {
    String retval= new String();
    Label l= e.getLabel();
    Instance ins= e.getInstance();
    retval += label.toString(l);
    int i=0;
    int s=ins.getSize();
    for(i=0; i < s; i++) {
      retval += ((AttributeDescription) attribute.get(i)).toString(e.getAttribute(i));
    }
    return(retval);
  }
  
  /** Converts the ExampleDescription into a String 
   *  the output is in the same format as a spec file.  			*/
  public String toString() {
    String retval=new String();
    for(int i=0; i<attribute.size(); i++) 
      retval += (AttributeDescription) attribute.get(i) + "\n";
    retval += label + "\n";
    return(retval);
  }
  
  public LabelDescription getLabelDescription() {
    return(label);
  }
  
  public AttributeDescription[] getAttributes() {
    AttributeDescription[] retval=new AttributeDescription[attribute.size()];
    for(int i=0;i<retval.length;i++) {
      retval[i]=(AttributeDescription)attribute.get(i);
    }
    return(retval);
  }
  
  /**
   * Return the number of attributes plus the Label and the example weight, if present
   * @return count
   */
  public int getNoOfAttributes() {
    return attribute.size();
  }
  
  public AttributeDescription getAttributeDescription(int i) {
    return (AttributeDescription) attribute.get(i);
  }
  
  
}