TiAda: A Time-scale Adaptive Algorithm for Nonconvex Minimax Optimization

Fuente: arXiv
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Autori principali: Li, Xiang, Yang, Junchi, He, Niao
Natura: Preprint
Pubblicazione: 2022
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author Li, Xiang
Yang, Junchi
He, Niao
author_facet Li, Xiang
Yang, Junchi
He, Niao
contents Adaptive gradient methods have shown their ability to adjust the stepsizes on the fly in a parameter-agnostic manner, and empirically achieve faster convergence for solving minimization problems. When it comes to nonconvex minimax optimization, however, current convergence analyses of gradient descent ascent (GDA) combined with adaptive stepsizes require careful tuning of hyper-parameters and the knowledge of problem-dependent parameters. Such a discrepancy arises from the primal-dual nature of minimax problems and the necessity of delicate time-scale separation between the primal and dual updates in attaining convergence. In this work, we propose a single-loop adaptive GDA algorithm called TiAda for nonconvex minimax optimization that automatically adapts to the time-scale separation. Our algorithm is fully parameter-agnostic and can achieve near-optimal complexities simultaneously in deterministic and stochastic settings of nonconvex-strongly-concave minimax problems. The effectiveness of the proposed method is further justified numerically for a number of machine learning applications.
format Preprint
id arxiv_https___arxiv_org_abs_2210_17478
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle TiAda: A Time-scale Adaptive Algorithm for Nonconvex Minimax Optimization
Li, Xiang
Yang, Junchi
He, Niao
Optimization and Control
Machine Learning
Adaptive gradient methods have shown their ability to adjust the stepsizes on the fly in a parameter-agnostic manner, and empirically achieve faster convergence for solving minimization problems. When it comes to nonconvex minimax optimization, however, current convergence analyses of gradient descent ascent (GDA) combined with adaptive stepsizes require careful tuning of hyper-parameters and the knowledge of problem-dependent parameters. Such a discrepancy arises from the primal-dual nature of minimax problems and the necessity of delicate time-scale separation between the primal and dual updates in attaining convergence. In this work, we propose a single-loop adaptive GDA algorithm called TiAda for nonconvex minimax optimization that automatically adapts to the time-scale separation. Our algorithm is fully parameter-agnostic and can achieve near-optimal complexities simultaneously in deterministic and stochastic settings of nonconvex-strongly-concave minimax problems. The effectiveness of the proposed method is further justified numerically for a number of machine learning applications.
title TiAda: A Time-scale Adaptive Algorithm for Nonconvex Minimax Optimization
topic Optimization and Control
Machine Learning
url https://arxiv.org/abs/2210.17478