The High Line: Exact Risk and Learning Rate Curves of Stochastic Adaptive Learning Rate Algorithms

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Collins-Woodfin, Elizabeth, Seroussi, Inbar, Malaxechebarría, Begoña García, Mackenzie, Andrew W., Paquette, Elliot, Paquette, Courtney
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909388440076288
author Collins-Woodfin, Elizabeth
Seroussi, Inbar
Malaxechebarría, Begoña García
Mackenzie, Andrew W.
Paquette, Elliot
Paquette, Courtney
author_facet Collins-Woodfin, Elizabeth
Seroussi, Inbar
Malaxechebarría, Begoña García
Mackenzie, Andrew W.
Paquette, Elliot
Paquette, Courtney
contents We develop a framework for analyzing the training and learning rate dynamics on a large class of high-dimensional optimization problems, which we call the high line, trained using one-pass stochastic gradient descent (SGD) with adaptive learning rates. We give exact expressions for the risk and learning rate curves in terms of a deterministic solution to a system of ODEs. We then investigate in detail two adaptive learning rates -- an idealized exact line search and AdaGrad-Norm -- on the least squares problem. When the data covariance matrix has strictly positive eigenvalues, this idealized exact line search strategy can exhibit arbitrarily slower convergence when compared to the optimal fixed learning rate with SGD. Moreover we exactly characterize the limiting learning rate (as time goes to infinity) for line search in the setting where the data covariance has only two distinct eigenvalues. For noiseless targets, we further demonstrate that the AdaGrad-Norm learning rate converges to a deterministic constant inversely proportional to the average eigenvalue of the data covariance matrix, and identify a phase transition when the covariance density of eigenvalues follows a power law distribution. We provide our code for evaluation at https://github.com/amackenzie1/highline2024.
format Preprint
id arxiv_https___arxiv_org_abs_2405_19585
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle The High Line: Exact Risk and Learning Rate Curves of Stochastic Adaptive Learning Rate Algorithms
Collins-Woodfin, Elizabeth
Seroussi, Inbar
Malaxechebarría, Begoña García
Mackenzie, Andrew W.
Paquette, Elliot
Paquette, Courtney
Optimization and Control
Statistics Theory
Machine Learning
We develop a framework for analyzing the training and learning rate dynamics on a large class of high-dimensional optimization problems, which we call the high line, trained using one-pass stochastic gradient descent (SGD) with adaptive learning rates. We give exact expressions for the risk and learning rate curves in terms of a deterministic solution to a system of ODEs. We then investigate in detail two adaptive learning rates -- an idealized exact line search and AdaGrad-Norm -- on the least squares problem. When the data covariance matrix has strictly positive eigenvalues, this idealized exact line search strategy can exhibit arbitrarily slower convergence when compared to the optimal fixed learning rate with SGD. Moreover we exactly characterize the limiting learning rate (as time goes to infinity) for line search in the setting where the data covariance has only two distinct eigenvalues. For noiseless targets, we further demonstrate that the AdaGrad-Norm learning rate converges to a deterministic constant inversely proportional to the average eigenvalue of the data covariance matrix, and identify a phase transition when the covariance density of eigenvalues follows a power law distribution. We provide our code for evaluation at https://github.com/amackenzie1/highline2024.
title The High Line: Exact Risk and Learning Rate Curves of Stochastic Adaptive Learning Rate Algorithms
topic Optimization and Control
Statistics Theory
Machine Learning
url https://arxiv.org/abs/2405.19585