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arXiv · 2102.03188

A simpler spectral approach for clustering in directed networks

Simon Coste·Ludovic Stephan
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Abstract

We study the task of clustering in directed networks. We show that using the eigenvalue/eigenvector decomposition of the adjacency matrix is simpler than all common methods which are based on a combination of data regularization and SVD truncation, and works well down to the very sparse regime where the edge density has constant order. Our analysis is based on a Master Theorem describing sharp asymptotics for isolated eigenvalues/eigenvectors of sparse, non-symmetric matrices with independent entries. We also describe the limiting distribution of the entries of these eigenvectors; in the task of digraph clustering with spectral embeddings, we provide numerical evidence for the superiority of Gaussian Mixture clustering over the widely used k-means algorithm.

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Simon Coste, Ludovic Stephan. 2021-02-05. A simpler spectral approach for clustering in directed networks. https://arxiv.org/abs/2102.03188

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