English

The Epsilon-Alternating Least Squares for Orthogonal Low-Rank Tensor Approximation and Its Global Convergence

Optimization and Control 2019-12-06 v3 Numerical Analysis Numerical Analysis

Abstract

The epsilon alternating least squares (ϵ\epsilon-ALS) is developed and analyzed for canonical polyadic decomposition (approximation) of a higher-order tensor where one or more of the factor matrices are assumed to be columnwisely orthonormal. It is shown that the algorithm globally converges to a KKT point for all tensors without any assumption. For the original ALS, by further studying the properties of the polar decomposition, we also establish its global convergence under a reality assumption not stronger than those in the literature. These results completely address a question concerning the global convergence raised in [L. Wang, M. T. Chu and B. Yu, \emph{SIAM J. Matrix Anal. Appl.}, 36 (2015), pp. 1--19]. In addition, an initialization procedure is proposed, which possesses a provable lower bound when the number of columnwisely orthonormal factors is one. Armed with this initialization procedure, numerical experiments show that the ϵ\epsilon-ALS exhibits a promising performance in terms of efficiency and effectiveness.

Keywords

Cite

@article{arxiv.1911.10921,
  title  = {The Epsilon-Alternating Least Squares for Orthogonal Low-Rank Tensor Approximation and Its Global Convergence},
  author = {Yuning Yang},
  journal= {arXiv preprint arXiv:1911.10921},
  year   = {2019}
}