= Network modularity
{title2=$Q=(2m)^{-1}\sum_{ij}(A_{ij}-k_ik_j/(2m))\mathbf1\{c_i=c_j\}$}
<Network modularity> measures excess within-community edge weight relative to a <network null model> based on <degrees of vertices>. For an undirected unweighted <graph>, its standard form is $Q=(2m)^{-1}\sum_{ij}(A_{ij}-k_ik_j/(2m))\mathbf1\{c_i=c_j\}$. A single community containing every <vertex> has $Q=0$; a partition with more internal connectivity than expected can have positive $Q$.
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