Statistical clustering of temporal networks through a dynamic stochastic block model

Catherine Matias (1) , Vincent Miele (2)

1 LPMA - Laboratoire de Probabilités et Modèles Aléatoires
2 LBBE - Laboratoire de Biométrie et Biologie Evolutive - UMR 5558

Statistical node clustering in discrete time dynamic networks is an emerging field that raises many challenges. Here, we explore statistical properties and deterministic inference in a model that combines a stochastic block model (SBM) for its static part with independent Markov chains for the evolution of the nodes groups through time. We model binary data as well as weighted dynamic random graphs (with discrete or continuous edges values). Our approach particularly focuses on the control for label switching issues across the different time steps. We study identifiability of the model parameters, propose an inference procedure based on a variational expectation maximization algorithm as well as a model selection criterion to select for the number of groups. We carefully discuss our initialization strategy which plays an important role in the method and compare our procedure with existing ones on synthetic datasets. We also illustrate our approach on a real data set of encounters among high school students and provide an implementation of the method into a R package called dynsbm.

Mots clés: graph clustering; dynamic random graph; stochastic block model; variational expectation maximization

Domaines: Mathématiques [math]; Statistiques [stat]

Catherine Matias, Vincent Miele. Statistical clustering of temporal networks through a dynamic stochastic block model: Clustering dynamic random graphs via SBM. 2015. ⟨hal-01167837v1⟩