public double get (int i)
	 {
	   switch (i)
	    { case 0:
	       { return x;
	       }
	      case 1:
	       { return y;
	       }
	      case 2:
	       { return z;
	       }
	      default:
	       { throw new ArrayIndexOutOfBoundsException (i);
	       }
	    }
	 }