How to show map distance text in android GMap v2

Question

I'm trying to show distance map in (in km) my applicatin. I implemented the code from this link Find distance between two points on map using Google Map API V2 - Abhijit Kurane

public double CalculiationByDistance(LatLng StartP, LatLng EndP) {
    int Radius = 6371;
    double lat1 = StartP.latitude;
    double lat2 = EndP.latitude;
    double lon1 = StartP.longitude;
    double lon2 = EndP.longitude;
    double dLat = Math.toRadians(lat2 - lat1);
    double dLon = Math.toRadians(lon2 - lon1);
    double a = Math.sin(dLat / 2) * Math.sin(dLat / 2)
            + Math.cos(Math.toRadians(lat1))
            * Math.cos(Math.toRadians(lat2)) * Math.sin(dLon / 2)
            * Math.sin(dLon / 2);
    double c = 2 * Math.asin(Math.sqrt(a));
    double valueResult = Radius * c;
    double km = valueResult / 1;
    DecimalFormat newFormat = new DecimalFormat("####");
    int kmInDec = Integer.valueOf(newFormat.format(km));
    double meter = valueResult % 1000;
    int meterInDec = Integer.valueOf(newFormat.format(meter));
    Log.i("Radius Value", "" + valueResult + "   KM  " + kmInDec
            + " Meter   " + meterInDec);

    return Radius * c;
}

but I only got the wrong distance, the logcat gives only 0.2 km distance. What should I do?

Thanks in advance..

score 0 · Answer 1 · answered Jan 22 '14 at 06:16

public static double distFrom(double lat1, double lng1, double lat2,
            double lng2) {
        double earthRadius = 3958.75;
        double dLat = Math.toRadians(lat2 - lat1);
        double dLng = Math.toRadians(lng2 - lng1);
        double sindLat = Math.sin(dLat / 2);
        double sindLng = Math.sin(dLng / 2);
        double a = Math.pow(sindLat, 2) + Math.pow(sindLng, 2)
                * Math.cos(Math.toRadians(lat1))
                * Math.cos(Math.toRadians(lat2));
        double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
        double dist = earthRadius * c;

        return dist;
    }


use as in KM like ::-->

distance = distFrom(latitude, longitude, lat_array.get(i),
                            long_array.get(i));
double km = distance / 0.62137;

How to show map distance text in android GMap v2

1 Answers1