AugmentedInstance.java :  » Natural-Language-Processing » MinorThird » edu » cmu » minorthird » classify » transform » Java Open Source

package edu.cmu.minorthird.classify.transform;

import edu.cmu.minorthird.classify.*;
import edu.cmu.minorthird.util.*;
import edu.cmu.minorthird.util.gui.*;

import java.util.*;

/** 
 * Add some features to an instance.
 * 
 * @author William Cohen
 */

public class AugmentedInstance implements Instance{

  private Instance instance;

  private Feature[] newFeatures;

  private double[] newValues;

  public AugmentedInstance(Instance instance,String[] newFeatureNames,
      double[] newVals){
    if(instance==null)
      throw new IllegalArgumentException("can't use null instance!");
    this.instance=instance;
    this.newFeatures=new Feature[newFeatureNames.length];
    this.newValues=new double[newVals.length];
    for(int i=0;i<newFeatureNames.length;i++){
      this.newFeatures[i]=new Feature(newFeatureNames[i]);
      this.newValues[i]=newVals[i];
    }
  }

  //
  // delegate to wrapped instance
  //
  final public Object getSource(){
    return instance.getSource();
  }

  final public String getSubpopulationId(){
    return instance.getSubpopulationId();
  }

  final public Iterator<Feature> binaryFeatureIterator(){
    return instance.binaryFeatureIterator();
  }

  //
  // extend the numeric feature set
  //

  final public Iterator<Feature> numericFeatureIterator(){
    return new UnionIterator<Feature>(new MyIterator(),instance
        .numericFeatureIterator());
  }

  final public Iterator<Feature> featureIterator(){
    return new UnionIterator<Feature>(new MyIterator(),instance
        .featureIterator());
  }
  
  final public int numFeatures(){
    return newFeatures.length+instance.numFeatures();
  }

  final public double getWeight(Feature f){
    for(int i=0;i<newFeatures.length;i++){
      if(newFeatures[i].equals(f)){
        return newValues[i];
      }
    }
    return instance.getWeight(f);
  }

  public String toString(){
    return "[AugmentedInstance: "+instance+StringUtil.toString(newFeatures)+
        StringUtil.toString(newValues)+"]";
  }

  final public Viewer toGUI(){
    return new GUI.InstanceViewer(this);
  }

  public class MyIterator implements Iterator<Feature>{

    private int i=0;

    public void remove(){
      throw new UnsupportedOperationException("can't remove");
    }

    public boolean hasNext(){
      return i<newFeatures.length;
    }

    public Feature next(){
      return newFeatures[i++];
    }
  }

  static public void main(String[] argv){
    MutableInstance inst=new MutableInstance();
    inst.addBinary(new Feature("william"));
    double[] vals=new double[argv.length];
    for(int i=0;i<vals.length;i++)
      vals[i]=i+1;
    AugmentedInstance aug=new AugmentedInstance(inst,argv,vals);
    System.out.println(aug.toString());
    for(int i=0;i<argv.length;i++){
      Feature f=new Feature(argv[i]);
      System.out.println("weight of "+f+"="+aug.getWeight(f));
    }
    for(Iterator<Feature> i=aug.featureIterator();i.hasNext();){
      Feature f=i.next();
      System.out.println("in aug: weight of "+f+"="+aug.getWeight(f));
    }
  }
}