| import networkx as nx | |
| __all__ = ["s_metric"] | |
| def s_metric(G): | |
| """Returns the s-metric [1]_ of graph. | |
| The s-metric is defined as the sum of the products ``deg(u) * deg(v)`` | |
| for every edge ``(u, v)`` in `G`. | |
| Parameters | |
| ---------- | |
| G : graph | |
| The graph used to compute the s-metric. | |
| Returns | |
| ------- | |
| s : float | |
| The s-metric of the graph. | |
| References | |
| ---------- | |
| .. [1] Lun Li, David Alderson, John C. Doyle, and Walter Willinger, | |
| Towards a Theory of Scale-Free Graphs: | |
| Definition, Properties, and Implications (Extended Version), 2005. | |
| https://arxiv.org/abs/cond-mat/0501169 | |
| """ | |
| return float(sum(G.degree(u) * G.degree(v) for (u, v) in G.edges())) | |