Campus Units
Electrical and Computer Engineering
Document Type
Conference Proceeding
Conference
36th International Conference on Machine Learning
Publication Version
Published Version
Publication Date
2019
Journal or Book Title
Proceedings of Machine Learning Research
Volume
97
First Page
4134
Last Page
4143
Conference Title
36th International Conference on Machine Learning
Conference Date
June 9-15, 2019
City
Long Beach, CA
Abstract
Alternating gradient descent (A-GD) is a simple but popular algorithm in machine learning, which updates two blocks of variables in an alternating manner using gradient descent steps. In this paper, we consider a smooth unconstrained nonconvex optimization problem, and propose a perturbed A-GD (PA-GD) which is able to converge (with high probability) to the second-order stationary points (SOSPs) with a global sublinear rate. Existing analysis on A-GD type algorithm either only guarantees convergence to first-order solutions, or converges to second-order solutions asymptotically (without rates). To the best of our knowledge, this is the first alternating type algorithm that takes O(polylog(d)/ϵ2) iterations to achieve an (ϵ,ϵ√)-SOSP with high probability, where polylog(d) denotes the polynomial of the logarithm with respect to problem dimension d.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Copyright Owner
The Author(s)
Copyright Date
2019
Language
en
File Format
application/pdf
Recommended Citation
Lu, Songtao; Hong, Mingyi; and Wang, Zhengdao, "PA-GD: On the Convergence of Perturbed Alternating Gradient Descent to Second-Order Stationary Points for Structured Nonconvex Optimization" (2019). Electrical and Computer Engineering Conference Papers, Posters and Presentations. 103.
https://lib.dr.iastate.edu/ece_conf/103
Comments
This proceeding is published as Lu, Songtao, Mingyi Hong, and Zhengdao Wang. "PA-GD: On the convergence of perturbed alternating gradient descent to second-order stationary points for structured nonconvex optimization." In International Conference on Machine Learning 97 (2019): 4134-4143. Posted with permission.