Precise Asymptotics for Spectral Methods in Mixed Generalized Linear Models

Fuente: arXiv
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Main Authors: Zhang, Yihan, Mondelli, Marco, Venkataramanan, Ramji
Format: Preprint
Published: 2022
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author Zhang, Yihan
Mondelli, Marco
Venkataramanan, Ramji
author_facet Zhang, Yihan
Mondelli, Marco
Venkataramanan, Ramji
contents In a mixed generalized linear model, the goal is to learn multiple signals from unlabeled observations: each sample comes from exactly one signal, but it is not known which one. We consider the prototypical problem of estimating two statistically independent signals in a mixed generalized linear model with Gaussian covariates. Spectral methods are a popular class of estimators which output the top two eigenvectors of a suitable data-dependent matrix. However, despite the wide applicability, their design is still obtained via heuristic considerations, and the number of samples $n$ needed to guarantee recovery is super-linear in the signal dimension $d$. In this paper, we develop exact asymptotics on spectral methods in the challenging proportional regime in which $n, d$ grow large and their ratio converges to a finite constant. This allows us optimize the design of the spectral method, and combine it with a simple linear estimator, to minimize the estimation error. Our characterization exploits a mix of tools from random matrices, free probability and the theory of approximate message passing algorithms. Numerical simulations for mixed linear regression and phase retrieval demonstrate the advantage enabled by our analysis over existing designs of spectral methods.
format Preprint
id arxiv_https___arxiv_org_abs_2211_11368
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Precise Asymptotics for Spectral Methods in Mixed Generalized Linear Models
Zhang, Yihan
Mondelli, Marco
Venkataramanan, Ramji
Statistics Theory
Information Theory
Machine Learning
In a mixed generalized linear model, the goal is to learn multiple signals from unlabeled observations: each sample comes from exactly one signal, but it is not known which one. We consider the prototypical problem of estimating two statistically independent signals in a mixed generalized linear model with Gaussian covariates. Spectral methods are a popular class of estimators which output the top two eigenvectors of a suitable data-dependent matrix. However, despite the wide applicability, their design is still obtained via heuristic considerations, and the number of samples $n$ needed to guarantee recovery is super-linear in the signal dimension $d$. In this paper, we develop exact asymptotics on spectral methods in the challenging proportional regime in which $n, d$ grow large and their ratio converges to a finite constant. This allows us optimize the design of the spectral method, and combine it with a simple linear estimator, to minimize the estimation error. Our characterization exploits a mix of tools from random matrices, free probability and the theory of approximate message passing algorithms. Numerical simulations for mixed linear regression and phase retrieval demonstrate the advantage enabled by our analysis over existing designs of spectral methods.
title Precise Asymptotics for Spectral Methods in Mixed Generalized Linear Models
topic Statistics Theory
Information Theory
Machine Learning
url https://arxiv.org/abs/2211.11368