Title
Online Variance Reduction for Stochastic Optimization.
Abstract
Modern stochastic optimization methods often rely on uniform sampling which is agnostic to the underlying characteristics of the data. This might degrade the convergence by yielding estimates that suffer from a high variance. A possible remedy is to employ non-uniform importance sampling techniques, which take the structure of the dataset into account. In this work, we investigate a recently proposed setting which poses variance reduction as an online optimization problem with bandit feedback. We devise a novel and efficient algorithm for this setting that finds a sequence of importance sampling distributions competitive with the best fixed distribution in hindsight, the first result of this kind. While we present our method for sampling datapoints, it naturally extends to selecting coordinates or even blocks of thereof. Empirical validations underline the benefits of our method in several settings.
Year
Venue
DocType
2018
conference on learning theory
Conference
Volume
Citations 
PageRank 
abs/1802.04715
0
0.34
References 
Authors
19
3
Name
Order
Citations
PageRank
Zalán Borsos151.79
Andreas Krause25822368.37
Kfir Y. Levy3728.77