Robust Rank Estimation for Noisy Matrices
Subhrajyoty Roy, Abhik Ghosh, Ayanendranath Basu
TL;DR
The paper addresses robustly estimating the true rank of a noisy data matrix by modeling it as a low-rank component plus sparse outliers and dense noise, and introduces a Divergence Information Criterion for Matrix Rank (DICMR) that leverages density power divergence with a robust SVD backbone. It establishes selection consistency and first-order robustness for DICMR, and demonstrates through extensive simulations that it rivals robust cross-validation at substantially lower computational cost. The method is validated on real data from microarray imputation (RNA-seq context), where DICMR-guided robust rank estimation yields improved reconstruction performance, highlighting practical significance for high-dimensional biological data analysis. While DICMR may overestimate rank for nearly square matrices, it provides a fast, reliable upper-bound estimator that can be integrated with more exhaustive search strategies or tensor generalizations in future work.
Abstract
Estimating the true rank of a noisy data matrix is a fundamental problem underlying techniques such as principal component analysis, matrix completion, etc. Existing rank estimation criteria, including information-based and cross-validation methods, are either highly sensitive to outliers or computationally demanding when combined with robust estimators. This paper proposes a new criterion, the Divergence Information Criterion for Matrix Rank (DICMR), that achieves both robustness and computational simplicity. Derived from the density power divergence framework, DICMR inherits the robustness properties while being computationally very simple. We provide asymptotic bounds on its overestimation and underestimation probabilities, and demonstrate first-order B-robustness of the criteria. Extensive simulations show that DICMR delivers accuracy comparable to the robustified cross-validation methods, but with far lower computational cost. We also showcase a real-data application to microarray imputation to further demonstrate its practical utility, outperforming several state-of-the-art algorithms.
