Linear Time Community Detection by a Novel Modularity Gain Acceleration in Label Propagation

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Department of Electrical and Computer Engineering


IEEE Community detection is an important problem in complex network analysis. Among numerous approaches for community detection, label propagation (LP) has attracted a lot of attention. LP selects the optimum community (i.e., label) of a network vertex by optimizing an objective function (e.g., Newman's modularity) subject to the available labels in the vicinity of the vertex. In this paper, a novel analysis of Newman's modularity gain with respect to label transitions in graphs is presented. Here, we propose a new form of Newman's modularity gain calculation that quantifies available label transitions for any LP based community detection. The proposed approach is called Modularity Gain Acceleration (MGA) and is simplified and divided into two components, the local and global sum-weights. The Local Sum-Weight (LSW) is the component with lower complexity and is calculated for each candidate label transition. The General Sum-Weight (GSW) is more computationally complex, and is calculated only once per each label. GSW is updated by leveraging a simple process for each node-label transition, instead of for all available labels. The MGA approach leads to significant efficiency improvements by reducing time consumption up to 85% relative to the original algorithms with the exact same quality in terms of modularity value which is highly valuable in analyses of big data sets.

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IEEE Transactions on Big Data