protected List filterNull( List ll )
protected static List filterNull( List ll )
	protected List filterNull( List ll )	{		ArrayList al = new ArrayList( );		for ( Iterator itr = ll.iterator( ); itr.hasNext( ); )		{			double[] obj = (double[]) itr.next( );			if ( obj == null || Double.isNaN( obj[0] ) || Double.isNaN( obj[1] ) )			{				continue;			}			al.add( obj );		}		return al;	}