Data.Utilities.java Source code

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Here is the source code for Data.Utilities.java

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/*
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package Data;

import DataBase.DataBase;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.List;
import org.apache.commons.math3.ml.clustering.Cluster;
import org.apache.commons.math3.ml.clustering.DoublePoint;
import org.apache.commons.math3.ml.clustering.DBSCANClusterer;

/**
 *
 * @author sergios
 */
public class Utilities {

    public static final Double R = 6372.8; // In kilometers

    public static Double haversine(double lat1, double lon1, double lat2, double lon2) {
        double dLat = Math.toRadians(lat2 - lat1);
        double dLon = Math.toRadians(lon2 - lon1);
        lat1 = Math.toRadians(lat1);
        lat2 = Math.toRadians(lat2);

        double a = Math.sin(dLat / 2) * Math.sin(dLat / 2)
                + Math.sin(dLon / 2) * Math.sin(dLon / 2) * Math.cos(lat1) * Math.cos(lat2);
        double c = 2 * Math.asin(Math.sqrt(a));
        return R * c;
    }

    public static Integer timeDiff(GPSRec rec1, GPSRec rec2) {

        Double t1 = (double) rec1.getTimestamp().getTime();
        Double t2 = (double) rec2.getTimestamp().getTime();

        Double timeDiff = Math.abs(t2 - t1);
        //        Double timeDiff = Math.abs(Double.longBitsToDouble(
        //                 - rec2.getTimestamp().getTime()));
        return (timeDiff.intValue());
    }

    public static Double distDiff(GPSRec rec1, GPSRec rec2) {

        return haversine(Double.parseDouble(rec1.getLatitude()), Double.parseDouble(rec1.getLongitude()),
                Double.parseDouble(rec2.getLatitude()), Double.parseDouble(rec2.getLongitude()));
    }

    public static Double distDiff(GPSRec rec1, AccessPoint rec2) {

        return haversine(Double.parseDouble(rec1.getLatitude()), Double.parseDouble(rec1.getLongitude()),
                Double.parseDouble(rec2.getLatitude()), Double.parseDouble(rec2.getLongitude()));
    }

    public static List<Cluster<DoublePoint>> DBSCANClusterer(ArrayList<StayPoint> stayPoints, Double eParam,
            Integer minClust) {

        DBSCANClusterer dbscan = new DBSCANClusterer(eParam, minClust);

        ArrayList<DoublePoint> input = new ArrayList<DoublePoint>();

        for (StayPoint st : stayPoints) {
            double coord[] = new double[2];
            coord[0] = Double.parseDouble(st.getLatitude());
            coord[1] = Double.parseDouble(st.getLongitude());
            input.add(new DoublePoint(coord));
        }

        List<Cluster<DoublePoint>> cluster = dbscan.cluster(input);

        return cluster;
    }

    public static DoublePoint getCentroid(Cluster<DoublePoint> dp) {

        double[] coords = new double[2];

        List<DoublePoint> clPoints = dp.getPoints();

        for (DoublePoint p : clPoints) {
            coords[0] += p.getPoint()[0];
            coords[1] += p.getPoint()[1];
        }

        coords[0] /= clPoints.size();
        coords[1] /= clPoints.size();

        return new DoublePoint(coords);
    }

}