public final static int hashLatLon(float lat,float lon){
  if (lat == -0f)   lat=0f;
  if (lon == -0f)   lon=0f;
  int tmp=Float.floatToIntBits(lat);
  int hash=(tmp << 5) | (tmp >> 27);
  return hash ^ Float.floatToIntBits(lon);
}

public final static int hashLatLon ( float lat , float lon ) { if ( lat == - 0f ) lat = 0f ; if ( lon == - 0f ) lon = 0f ; int tmp = Float . floatToIntBits ( lat ) ; int hash = ( tmp << 5 ) | ( tmp > > 27 ) ; return hash ^ Float . floatToIntBits ( lon ) ; }
generate a hashcode value for a lat / lon pair .
