protected double findMaxAltitude(List<? extends Position> positions){
  double maxAltitude=-Double.MAX_VALUE;
  for (  Position p : positions) {
    double altitude=p.getAltitude();
    if (altitude > maxAltitude)     maxAltitude=altitude;
  }
  return maxAltitude;
}

protected double findMaxAltitude ( List < ? extends Position > positions ) { double maxAltitude = - Double . MAX_VALUE ; for ( Position p : positions ) { double altitude = p . getAltitude ( ) ; if ( altitude > maxAltitude ) maxAltitude = altitude ; } return maxAltitude ; }
get the maximum altitude in a list of positions .
