Here comes the Sun

import java.util.ArrayList;
import java.util.Collection;

import com.vividsolutions.jts.geom.Coordinate;
import com.vividsolutions.jts.geom.Geometry;
import com.vividsolutions.jts.geom.GeometryCollection;
import com.vividsolutions.jts.geom.GeometryFactory;
import com.vividsolutions.jts.triangulate.DelaunayTriangulationBuilder;
import com.vividsolutions.jts.triangulate.VoronoiDiagramBuilder;

/**
 *
 * @author Sun Ning/SNDA
 * @since 2010-3-3
 */
public class DelaunayAndVoronoiApp {

    /**
     * create some predefined sites
     * @return
     */
    public static Collection<coordinate> getPredefinedSites(){
        double[][] coords =  {{100,27},{28, 50},{29,
     40},{32, 90}, {12, 26  }};
        ArrayList<coordinate> coordinates = new ArrayList<coordinate>(coords.length);</coordinate></coordinate></coordinate>

        for(int i=0; i<coords.length; i++){
            coordinates.add(new Coordinate(coords[i][0], coords[i][1]));
        }

        return coordinates;
    }

    /**
     *
     * @param coords
     * @return a geometry collection of triangulations
     */
    public static Geometry buildDelaunayTriangulation(Collection<coordinate> coords){
        DelaunayTriangulationBuilder builder = new DelaunayTriangulationBuilder();
        builder.setSites(coords);
        return builder.getTriangles(new GeometryFactory());
    }
    /**
     *
     * @param coords
     * @return a collection of polygons
     */
    public static Geometry buildVoronoiDiagram(Collection<coordinate> coords){
        VoronoiDiagramBuilder builder = new VoronoiDiagramBuilder();
        builder.setSites(coords);
        return builder.getDiagram(new GeometryFactory());
    }</coordinate></coordinate>

    /**
     *
     * @param args
     */
    public static void main(String[] args){
        Collection<coordinate> coordinates = getPredefinedSites();</coordinate>

        /**
         * Delauny
         */
        GeometryCollection triangulations
                = (GeometryCollection)buildDelaunayTriangulation(coordinates);

        int total = triangulations.getNumGeometries();
        System.out.printf("Total triangulations: %d\n", total);
        for(int i=0; i<total; i++){
            Geometry g = triangulations.getGeometryN(i);
            Coordinate[] coords = g.getCoordinates();
            System.out.printf("Triangulation %d: ", i);
            for(Coordinate c : coords){
                System.out.printf("(%.3f, %.3f) ", c.x, c.y);
            }
            System.out.println();
        }

        /**
         * Voronoi
         */
        GeometryCollection diagram = (GeometryCollection)
                buildVoronoiDiagram(coordinates);
        int totalDia = diagram.getNumGeometries();
        for(int i=0; i<totalDia; i++){
            Geometry g = diagram.getGeometryN(i);
            Coordinate[] coords = g.getCoordinates();
            System.out.printf("Diagram %d: ", i);
            for(Coordinate c : coords){
                System.out.printf("(%.3f, %.3f) ", c.x, c.y);
            }
            System.out.println();
        }
    }

}