Kernel PCA for multivariate extremes
- URL: http://arxiv.org/abs/2211.13172v2
- Date: Thu, 24 Nov 2022 02:58:34 GMT
- Title: Kernel PCA for multivariate extremes
- Authors: Marco Avella-Medina, Richard A. Davis and Gennady Samorodnitsky
- Abstract summary: We show that kernel PCA can be a powerful tool for clustering and dimension reduction.
We give theoretical guarantees on the performance of kernel PCA based on an extremal sample.
Our findings are complemented by numerical experiments illustrating the finite performance of our methods.
- Score: 0.0
- License: http://creativecommons.org/licenses/by-nc-sa/4.0/
- Abstract: We propose kernel PCA as a method for analyzing the dependence structure of
multivariate extremes and demonstrate that it can be a powerful tool for
clustering and dimension reduction. Our work provides some theoretical insight
into the preimages obtained by kernel PCA, demonstrating that under certain
conditions they can effectively identify clusters in the data. We build on
these new insights to characterize rigorously the performance of kernel PCA
based on an extremal sample, i.e., the angular part of random vectors for which
the radius exceeds a large threshold. More specifically, we focus on the
asymptotic dependence of multivariate extremes characterized by the angular or
spectral measure in extreme value theory and provide a careful analysis in the
case where the extremes are generated from a linear factor model. We give
theoretical guarantees on the performance of kernel PCA preimages of such
extremes by leveraging their asymptotic distribution together with Davis-Kahan
perturbation bounds. Our theoretical findings are complemented with numerical
experiments illustrating the finite sample performance of our methods.
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