public double azimuth(Geo v2){
  double ret=strictAzimuth(v2);
  if (Double.isNaN(ret)) {
    return 0;
  }
  return ret;
}

public double azimuth ( Geo v2 ) { double ret = strictAzimuth ( v2 ) ; if ( Double . isNaN ( ret ) ) { return 0 ; } return ret ; }
azimuth in radians from v2 to this .
