/**
* See
* http://gis.stackexchange.com/questions/29239/calculate-bearing-between-two-decimal-gps-coordinates
*
* @param start
* @param end
* @return
*/
public static double getBearing(Location start, Location end) {
double startLong = toRadians(start.getLongitude());
double startLat = toRadians(start.getLatitude());
double endLong = toRadians(end.getLongitude());
double endLat = toRadians(end.getLatitude());
double dLong = endLong - startLong;
double dPhi = Math.log(tan(endLat / 2.0 + Math.PI / 4.0) / tan(startLat / 2.0 + Math.PI / 4.0));
if (Math.abs(dLong) > Math.PI) {
if (dLong > 0.0) dLong = -(2.0 * Math.PI - dLong);
else dLong = (2.0 * Math.PI + dLong);
}
return (toDegrees(Math.atan2(dLong, dPhi)) + 360.0) % 360.0;
}
private static Location getMidpoint(Location start, Location end) {
double startLat = toRadians(start.getLatitude());
double startLong = toRadians(start.getLongitude());
double endLat = toRadians(end.getLatitude());
double deltaLong = toRadians(end.getLongitude() - start.getLongitude());
double Bx = cos(endLat) * cos(deltaLong);
double By = cos(endLat) * sin(deltaLong);
double midLat =
Math.atan2(
sin(startLat) + sin(endLat),
Math.sqrt((cos(startLat) + Bx) * (cos(startLat) + Bx) + By * By));
double midLong = startLong + Math.atan2(By, cos(startLat) + Bx);
midLong = (midLong + 3 * Math.PI) % (2 * Math.PI) - Math.PI; // normalize to -180..+180°
return new Location(toDegrees(midLat), toDegrees(midLong));
}
@Override
public int compare(Location o1, Location o2) {
if (Double.compare(o1.getLongitude(), o2.getLongitude()) == 0)
return reverseDirection * Double.compare(o1.getLatitude(), o2.getLatitude());
return reverseDirection * Double.compare(o1.getLongitude(), o2.getLongitude());
}
public LocationComparator(Location start, Location end) {
if (Double.compare(start.getLongitude(), end.getLongitude()) == 0)
reverseDirection = -1 * Double.compare(start.getLatitude(), end.getLatitude());
reverseDirection = -1 * Double.compare(start.getLongitude(), end.getLongitude());
}