fieldstringdistancepipe.java

这是一个matlab的java实现。里面有许多内容。请大家慢慢捉摸。

package edu.umass.cs.mallet.projects.seg_plus_coref.coreference;

import com.wcohen.secondstring.StringDistance;
import com.wcohen.secondstring.NeedlemanWunsch;
import edu.umass.cs.mallet.base.pipe.Pipe;
import edu.umass.cs.mallet.base.types.Instance;
import edu.umass.cs.mallet.projects.seg_plus_coref.coreference.Citation;
import edu.umass.cs.mallet.projects.seg_plus_coref.coreference.NodePair;

/**
 * FieldStringDistancePipe
 * User: mhay
 * Email: [e-mail]
 * Date: Feb 18, 2004 4:40:24 PM
 */

public class FieldStringDistancePipe extends Pipe {
    StringDistance distanceMeasure;
    private String[] fields;
    private String featureName;


    public FieldStringDistancePipe(StringDistance distanceMeasure,
				   String[] fields, String featureName) {
	this.distanceMeasure = distanceMeasure;
	this.fields = fields;
	this.featureName = featureName;
    }

    public Instance pipe (Instance carrier) {
	NodePair pair = (NodePair)carrier.getData();
	Citation c1 = (Citation)pair.getObject1();
	Citation c2 = (Citation)pair.getObject2();

	if (true) {
	    for (int i = 0; i < fields.length; i++) {
		String fieldName = fields[i];

		// filter: don't look at these fields since they're
		// collapsed in venue anyway
		// don't include year because soft matching is dangerous
		// with it
		if (!fieldName.equals("booktitle") &&
		    !fieldName.equals("tech") &&
		    !fieldName.equals("journal") &&
		    !fieldName.equals("year")) {
		    String f1 = c1.getField(fieldName);
		    String f2 = c2.getField(fieldName);
		    if (f1.length() > 0 && f2.length() > 0) {
			double dist = 0.0;
			if (distanceMeasure instanceof NeedlemanWunsch) {
			    dist = 1 - ((Math.abs(distanceMeasure.score(f1, f2)) /
					 (double)(f1.length() + f2.length())));
			} else
			    dist = distanceMeasure.score(f1,f2);
			if (dist > 0.01)
			    pair.setFeatureValue(featureName+"_"+fieldName, dist);
			else
			    pair.setFeatureValue(featureName+"_"+fieldName+"LOW", dist);
		    } else if ((f1.length() == 0 && f2.length() > 0) ||
			       (f1.length() > 0 && f2.length() == 0))
			pair.setFeatureValue("onlyOne"+fieldName, 1.0);
		    else
			pair.setFeatureValue("neitherHave"+fieldName, 1.0);
		}
	    }
	}
	if (false) {
	    for (int i = 0; i < fields.length; i++) {
		String fieldName = fields[i];
		String f1 = c1.getField(fieldName);
		String f2 = c2.getField(fieldName);

		if (f1.length() > 0 && f2.length() > 0) {
		    double dist = 0.0;
		    if (distanceMeasure instanceof NeedlemanWunsch) {
			dist = 1 - ((Math.abs(distanceMeasure.score(f1, f2)) /
				     (double)(f1.length() + f2.length())));
		    } else
			dist = distanceMeasure.score(f1,f2);
		    if (dist >= 0.9)
			pair.setFeatureValue(featureName+"_"+fieldName+"HIGH", dist);
		    else if (dist > 0.75)
			pair.setFeatureValue(featureName+"_"+fieldName+"MED", dist);
		    else if (dist > 0.5)
			pair.setFeatureValue(featureName+"_"+fieldName+"WEAK", dist);
		    else if (dist > 0.3)
			pair.setFeatureValue(featureName+"_"+fieldName+"MIN", dist);
		    else if (dist < 0.3)
			pair.setFeatureValue(featureName+"_"+fieldName+"NONE", dist);
		} else if ((f1.length() == 0 && f2.length() > 0) ||
			   (f1.length() > 0 && f2.length() == 0))
		    pair.setFeatureValue("onlyOne"+fieldName, 1.0);
		else
		    pair.setFeatureValue("neitherHave"+fieldName, 1.0);
	    }

	}
	return carrier;
    }
}