Variational Bayesian inference for CP tensor completion with side information
Stanislav Budzinskiy, Nikolai Zamarashkin
TL;DR
The paper addresses CP tensor completion under limited observations by introducing a variational Bayesian framework that incorporates side information in the form of low-dimensional subspaces. It derives a closed-form, message-passing VB algorithm that jointly infers CP factors, hyperparameters, and an automatic effective rank through Gamma priors, extending the matrix case to tensors. Empirical results on synthetic data and real 3D Basel Face Model data show substantial reductions in the required number of observed entries when side information is available, along with insights into phase-transition behavior and rank determination. The work highlights the regularization benefits and practical impact of side information for tensor completion in data-scarce regimes.
Abstract
We propose a message passing algorithm, based on variational Bayesian inference, for low-rank tensor completion with automatic rank determination in the canonical polyadic format when additional side information (SI) is given. The SI comes in the form of low-dimensional subspaces the contain the fiber spans of the tensor (columns, rows, tubes, etc.). We validate the regularization properties induced by SI with extensive numerical experiments on synthetic and real-world data and present the results about tensor recovery and rank determination. The results show that the number of samples required for successful completion is significantly reduced in the presence of SI. We also discuss the origin of a bump in the phase transition curves that exists when the dimensionality of SI is comparable with that of the tensor.
