distancemeasure.java

著名的开源仿真软件yale

package edu.udo.cs.yale.operator.clusterer.upgma;

import edu.udo.cs.yale.example.Example;
import edu.udo.cs.yale.example.ExampleSet;
import edu.udo.cs.yale.example.ExampleReader;

public abstract class DistanceMeasure {

    public static final String[] CLUSTER_TYPE_NAMES = new String[] {"minimum", "maximum", "average", "unweighted_average" };
    public static final int TYPE_MINIMUM = 0;
    public static final int TYPE_MAXIMUM = 1;
    public static final int TYPE_AVERAGE = 2;
    public static final int TYPE_UNWEIGHTED = 3;

    public static final String[] TYPE_NAMES = new String[] {"euklidian", "nominal"};
    public static final int TYPE_EUKLIDIAN = 0;
    public static final int TYPE_NOMINAL   = 1;

    public static ClusterDistanceMeasure createClusterDistanceMeasure(int type) {
	switch (type) {
	case TYPE_MINIMUM: return new MinClusterDistanceMeasure();
	case TYPE_MAXIMUM: return new MaxClusterDistanceMeasure();
	case TYPE_AVERAGE: return new AverageClusterDistanceMeasure();
	case TYPE_UNWEIGHTED: return new UnweightedClusterDistanceMeasure();
	default:
	    throw new IllegalArgumentException("Illegal ClusterDistanceMeasure type: "+type);
	}
    }

    public static DistanceMeasure createDistanceMeasure(int type) {
	switch (type) {
	case TYPE_EUKLIDIAN: return new EuklidianDistanceMeasure();
	case TYPE_NOMINAL:   return new NominalDistanceMeasure();
	default:
	    throw new IllegalArgumentException("Illegal DistanceMeasure type: "+type);
	}
    }

    public abstract double calculateDistance(Example e1, Example e2);

    public DistanceMatrix calculateDistanceMatrix(ExampleSet exampleSet) {
	DistanceMatrix matrix = new DistanceMatrix(exampleSet.getSize());
	ExampleReader r = exampleSet.getExampleReader();
	int i = 0;
	while (r.hasNext()) {
	    Example e = r.next();
	    String name = "?";
	    if (e.getIdAttribute() != null) {
		String idString = e.getIdAsString();
		if (idString.length() > 15)
		    name = idString.substring(0,15) + "...";
		else name = idString;
		if (e.getLabelAttribute() != null) {
		    name += "\n(" + e.getLabelAsString() + ")";
		}
	    } else if (e.getLabelAttribute() != null) {
		name = e.getLabelAsString();
	    }

	    matrix.setName(i, name);
	    ExampleReader s = exampleSet.getExampleReader();
	    int j = 0;
	    while (s.hasNext()) {
		matrix.setDistance(i, j, calculateDistance(e, s.next()));		
		j++;
	    }
	    i++;
	}
	return matrix;
    }

}