Title
Painless Stochastic Gradient: Interpolation, Line-Search, and Convergence Rates.
Abstract
Recent works have shown that stochastic gradient descent (SGD) achieves the fast convergence rates of full-batch gradient descent for over-parameterized models satisfying certain interpolation conditions. However, the step-size used in these works depends on unknown quantities and SGD's practical performance heavily relies on the choice of this step-size. We propose to use line-search techniques to automatically set the step-size when training models that can interpolate the data. In the interpolation setting, we prove that SGD with a stochastic variant of the classic Armijo line-search attains the deterministic convergence rates for both convex and strongly-convex functions. Under additional assumptions, SGD with Armijo line-search is shown to achieve fast convergence for non-convex functions. Furthermore, we show that stochastic extra-gradient with a Lipschitz line-search attains linear convergence for an important class of non-convex functions and saddle-point problems satisfying interpolation. To improve the proposed methods' practical performance, we give heuristics to use larger step-sizes and acceleration. We compare the proposed algorithms against numerous optimization methods on standard classification tasks using both kernel methods and deep networks. The proposed methods result in competitive performance across all models and datasets, while being robust to the precise choices of hyper-parameters. For multi-class classification using deep networks, SGD with Armijo line-search results in both faster convergence and better generalization.
Year
Venue
Keywords
2019
ADVANCES IN NEURAL INFORMATION PROCESSING SYSTEMS 32 (NIPS 2019)
kernel methods,search results,unknown quantities
Field
DocType
Volume
Convergence (routing),Mathematical optimization,Stochastic gradient descent,Gradient descent,Interpolation,Line search,Lipschitz continuity,Rate of convergence,Kernel method,Mathematics
Journal
32
ISSN
Citations 
PageRank 
1049-5258
0
0.34
References 
Authors
0
6
Name
Order
Citations
PageRank
Sharan Vaswani192.91
Mishkin, Aaron220.69
Issam H. Laradji3799.40
Mark W. Schmidt4129584.47
Gauthier Gidel5228.91
Simon Lacoste-Julien6113862.72