Alternating minimization for generalized rank one matrix sensing: Sharp predictions from a random initialization

Fuente: arXiv
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Autori principali: Chandrasekher, Kabir Aladin, Lou, Mengqi, Pananjady, Ashwin
Natura: Preprint
Pubblicazione: 2022
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author Chandrasekher, Kabir Aladin
Lou, Mengqi
Pananjady, Ashwin
author_facet Chandrasekher, Kabir Aladin
Lou, Mengqi
Pananjady, Ashwin
contents We consider the problem of estimating the factors of a rank-$1$ matrix with i.i.d. Gaussian, rank-$1$ measurements that are nonlinearly transformed and corrupted by noise. Considering two prototypical choices for the nonlinearity, we study the convergence properties of a natural alternating update rule for this nonconvex optimization problem starting from a random initialization. We show sharp convergence guarantees for a sample-split version of the algorithm by deriving a deterministic recursion that is accurate even in high-dimensional problems. Notably, while the infinite-sample population update is uninformative and suggests exact recovery in a single step, the algorithm -- and our deterministic prediction -- converges geometrically fast from a random initialization. Our sharp, non-asymptotic analysis also exposes several other fine-grained properties of this problem, including how the nonlinearity and noise level affect convergence behavior. On a technical level, our results are enabled by showing that the empirical error recursion can be predicted by our deterministic sequence within fluctuations of the order $n^{-1/2}$ when each iteration is run with $n$ observations. Our technique leverages leave-one-out tools originating in the literature on high-dimensional $M$-estimation and provides an avenue for sharply analyzing higher-order iterative algorithms from a random initialization in other high-dimensional optimization problems with random data.
format Preprint
id arxiv_https___arxiv_org_abs_2207_09660
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Alternating minimization for generalized rank one matrix sensing: Sharp predictions from a random initialization
Chandrasekher, Kabir Aladin
Lou, Mengqi
Pananjady, Ashwin
Optimization and Control
Probability
Statistics Theory
Machine Learning
We consider the problem of estimating the factors of a rank-$1$ matrix with i.i.d. Gaussian, rank-$1$ measurements that are nonlinearly transformed and corrupted by noise. Considering two prototypical choices for the nonlinearity, we study the convergence properties of a natural alternating update rule for this nonconvex optimization problem starting from a random initialization. We show sharp convergence guarantees for a sample-split version of the algorithm by deriving a deterministic recursion that is accurate even in high-dimensional problems. Notably, while the infinite-sample population update is uninformative and suggests exact recovery in a single step, the algorithm -- and our deterministic prediction -- converges geometrically fast from a random initialization. Our sharp, non-asymptotic analysis also exposes several other fine-grained properties of this problem, including how the nonlinearity and noise level affect convergence behavior. On a technical level, our results are enabled by showing that the empirical error recursion can be predicted by our deterministic sequence within fluctuations of the order $n^{-1/2}$ when each iteration is run with $n$ observations. Our technique leverages leave-one-out tools originating in the literature on high-dimensional $M$-estimation and provides an avenue for sharply analyzing higher-order iterative algorithms from a random initialization in other high-dimensional optimization problems with random data.
title Alternating minimization for generalized rank one matrix sensing: Sharp predictions from a random initialization
topic Optimization and Control
Probability
Statistics Theory
Machine Learning
url https://arxiv.org/abs/2207.09660