public SidedPlane(Vector p,final PlanetModel planetModel,double sinLat){
  super(planetModel,sinLat);
  sigNum=Math.signum(evaluate(p));
  if (sigNum == 0.0)   throw new IllegalArgumentException("Cannot determine sidedness because check point is on plane.");
}

public SidedPlane ( Vector p , final PlanetModel planetModel , double sinLat ) { super ( planetModel , sinLat ) ; sigNum = Math . signum ( evaluate ( p ) ) ; if ( sigNum == 0.0 ) throw new IllegalArgumentException ( "Cannot determine sidedness because check point is on plane." ) ; }
construct a sided plane from a point and a z coordinate .
