Title
An Improved Gap-Dependency Analysis of the Noisy Power Method.
Abstract
We consider the noisy power method algorithm, which has wide applications in machine learning and statistics, especially those related to principal component analysis (PCA) under resource (communication, memory or privacy) constraints. Existing analysis of the noisy power method shows an unsatisfactory dependency over the consecutive spectral gap $(sigma_k-sigma_{k+1})$ of an input data matrix, which could be very small and hence limits the algorithmu0027s applicability. In this paper, we present a new analysis of the noisy power method that achieves improved gap dependency for both sample complexity and noise tolerance bounds. More specifically, we improve the dependency over $(sigma_k-sigma_{k+1})$ to dependency over $(sigma_k-sigma_{q+1})$, where $q$ is an intermediate algorithm parameter and could be much larger than the target rank $k$. Our proofs are built upon a novel characterization of proximity between two subspaces that differ from canonical angle characterizations analyzed in previous works. Finally, we apply our improved bounds to distributed private PCA and memory-efficient streaming PCA and obtain bounds that are superior to existing results in the literature.
Year
Venue
DocType
2016
COLT
Conference
Volume
Citations 
PageRank 
abs/1602.07046
9
0.51
References 
Authors
17
4
Name
Order
Citations
PageRank
Maria-Florina Balcan11445105.01
Simon Du221029.79
Yining Wang36815.27
Adams Wei Yu41418.79