Source code for networkx.algorithms.smetric

import networkx as nx

__all__ = ["s_metric"]


[docs] @nx._dispatchable def s_metric(G, **kwargs): """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. normalized : bool (optional) Normalize the value. .. deprecated:: 3.2 The `normalized` keyword argument is deprecated and will be removed in the future 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 """ # NOTE: This entire code block + the **kwargs in the signature can all be # removed when the deprecation expires. # Normalized is always False, since all `normalized=True` did was raise # a NotImplementedError if kwargs: # Warn for `normalize`, raise for any other kwarg if "normalized" in kwargs: import warnings warnings.warn( "\n\nThe `normalized` keyword is deprecated and will be removed\n" "in the future. To silence this warning, remove `normalized`\n" "when calling `s_metric`.\n\n" "The value of `normalized` is ignored.", DeprecationWarning, stacklevel=3, ) else: # Typical raising behavior for Python when kwarg not recognized raise TypeError( f"s_metric got an unexpected keyword argument '{list(kwargs.keys())[0]}'" ) return float(sum(G.degree(u) * G.degree(v) for (u, v) in G.edges()))