Graph Local Overlap Measure: Sorensen Index

The Sorensen index is

$$ \mathbf S_{\text{Sorensen}}[u,v] = \frac{ 2\lvert \mathcal N (u) \cap \mathcal N(v) \rvert }{ d_u + d_v}, $$

where $d_u$ is the node degree of node $u$ and $\mathcal N(u)$ is the neighbor nodes of $u$.