1. Rank $2r$ iterative least squares: efficient recovery of ill-conditioned low rank matrices from few entries
- Author
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Bauch, Jonathan, Nadler, Boaz, Zilber, Pini, Bauch, Jonathan, Nadler, Boaz, and Zilber, Pini
- Abstract
We present a new, simple and computationally efficient iterative method for low rank matrix completion. Our method is inspired by the class of factorization-type iterative algorithms, but substantially differs from them in the way the problem is cast. Precisely, given a target rank $r$, instead of optimizing on the manifold of rank $r$ matrices, we allow our interim estimated matrix to have a specific over-parametrized rank $2r$ structure. Our algorithm, denoted R2RILS for rank $2r$ iterative least squares, has low memory requirements, and at each iteration it solves a computationally cheap sparse least-squares problem. We motivate our algorithm by its theoretical analysis for the simplified case of a rank-1 matrix. Empirically, R2RILS is able to recover ill conditioned low rank matrices from very few observations -- near the information limit, and it is stable to additive noise.
- Published
- 2020
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