Saved in:
Bibliographic Details
Main Authors: Kim, Younghoon, Loh, Po-Ling, Basu, Sumanta
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2510.13715
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914095307948032
author Kim, Younghoon
Loh, Po-Ling
Basu, Sumanta
author_facet Kim, Younghoon
Loh, Po-Ling
Basu, Sumanta
contents We develop an exact coordinate descent algorithm for high-dimensional regularized Huber regression. In contrast to composite gradient descent methods, our algorithm fully exploits the advantages of coordinate descent when the underlying model is sparse. Moreover, unlike existing second-order approximation methods previously introduced in the literature, it remains effective even when the Hessian becomes ill-conditioned due to high correlations among covariates drawn from heavy-tailed distributions. The key idea is that, for each coordinate, marginal increments arise only from inlier observations, while the derivatives remain monotonically increasing over a grid constructed from the partial residuals. Building on conventional coordinate descent strategies, we further propose variable screening rules that selectively determine which variables to update at each iteration, thereby accelerating convergence. To the best of our knowledge, this is the first work to develop a first-order coordinate descent algorithm for penalized Huber loss minimization. We bound the nonasymptotic convergence rate of the proposed algorithm by extending arguments developed for the Lasso and formally characterize the operation of the proposed screening rule. Extensive simulation studies under heavy-tailed and highly-correlated predictors, together with a real data application, demonstrate both the practical efficiency of the method and the benefits of the computational enhancements.
format Preprint
id arxiv_https___arxiv_org_abs_2510_13715
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Exact Coordinate Descent for High-Dimensional Regularized Huber Regression
Kim, Younghoon
Loh, Po-Ling
Basu, Sumanta
Methodology
We develop an exact coordinate descent algorithm for high-dimensional regularized Huber regression. In contrast to composite gradient descent methods, our algorithm fully exploits the advantages of coordinate descent when the underlying model is sparse. Moreover, unlike existing second-order approximation methods previously introduced in the literature, it remains effective even when the Hessian becomes ill-conditioned due to high correlations among covariates drawn from heavy-tailed distributions. The key idea is that, for each coordinate, marginal increments arise only from inlier observations, while the derivatives remain monotonically increasing over a grid constructed from the partial residuals. Building on conventional coordinate descent strategies, we further propose variable screening rules that selectively determine which variables to update at each iteration, thereby accelerating convergence. To the best of our knowledge, this is the first work to develop a first-order coordinate descent algorithm for penalized Huber loss minimization. We bound the nonasymptotic convergence rate of the proposed algorithm by extending arguments developed for the Lasso and formally characterize the operation of the proposed screening rule. Extensive simulation studies under heavy-tailed and highly-correlated predictors, together with a real data application, demonstrate both the practical efficiency of the method and the benefits of the computational enhancements.
title Exact Coordinate Descent for High-Dimensional Regularized Huber Regression
topic Methodology
url https://arxiv.org/abs/2510.13715