 However, given an n-vertex weighted planar graph, the best upper bound  is only O(\log n)  by Rao [SoCG99].
<meaning-changed>  However, given an n-vertex weighted planar graph, the best upper bound  is only O(\log n)  by Rao [SoCG99].
 However, given an n-vertex weighted planar graph, the best upper bound on the distortion is only O(\log n) by Rao [SoCG99].