Title
Fast Statistical Leverage Score Approximation In Kernel Ridge Regression
Abstract
Nystrom approximation is a fast randomized method that rapidly solves kernel ridge regression (KRR) problems through subsampling the n-by-n empirical kernel matrix appearing in the objective function. However, the performance of such a sub-sampling method heavily relies on correctly estimating the statistical leverage scores for forming the sampling distribution, which can be as costly as solving the original KRR. In this work, we propose a linear time (modulo polylog terms) algorithm to accurately approximate the statistical leverage scores in the stationary-kernel-based KRR with theoretical guarantees. Particularly, by analyzing the first-order condition of the KRR objective, we derive an analytic formula, which depends on both the input distribution and the spectral density of stationary kernels, for capturing the non-uniformity of the statistical leverage scores. Numerical experiments demonstrate that with the same prediction accuracy our method is orders of magnitude more efficient than existing methods in selecting the representative sub-samples in the Nystrom approximation.
Year
Venue
DocType
2021
24TH INTERNATIONAL CONFERENCE ON ARTIFICIAL INTELLIGENCE AND STATISTICS (AISTATS)
Conference
Volume
ISSN
Citations 
130
2640-3498
0
PageRank 
References 
Authors
0.34
0
2
Name
Order
Citations
PageRank
Yifan Chen15819.82
Yun Yang200.34