public double distanceNM() {  return distanceKM()/1.852;
public double distanceNM(double lat1, double lon1, double lat2, double lon2) { this.setPoint1(lat1, lon1); return distanceNM(lat2, lon2);
  public double distanceNM() {    // http://forum.swarthmore.edu/pow/solutio69.html    return distanceKM()/1.852;  }