vix.ing · top · new · best · stats

Hilbert space methods for reduced-rank Gaussian process regression

2014/01/31 by Arno Solin, Simo Särkkä · 1 voice · 134 citations
Computer Science · Mathematics · #Advanced Multi-Objective Optimization Algorithms #Covariance #Covariance function #Covariance operator #Eigenfunction #Gaussian Processes and Bayesian Inference #Gaussian process #Hilbert space #Matérn covariance function #Rational quadratic covariance function #Reproducing kernel Hilbert space #Stochastic Gradient Optimization Techniques #stat.ML

paper · pdf · doi:10.1007/s11222-019-09886-w

published in Statistics and Computing 30(2), 419-446 (Springer Science+Business Media)

openalex created_date 2016/06/24 · arxiv created 2019/08/01 · openalex publication_date 2019/08/05 · arxiv updated 2020/06/26 · openalex updated_date 2026/08/06

Abstract

This paper proposes a novel scheme for reduced-rank Gaussian process regression. The method is based on an approximate series expansion of the covariance function in terms of an eigenfunction expansion of the Laplace operator in a compact subset of \(\mathbb Rd\) . On this approximate eigenbasis, the eigenvalues of the covariance function can be expressed as simple functions of the spectral density of the Gaussian process, which allows the GP inference to be solved under a computational cost scaling as \(\mathcal O(nm2)\) (initial) and \(\mathcal O(m3)\) (hyperparameter learning) with m basis functions and n data points. Furthermore, the basis functions are independent of the parameters of the covariance function, which allows for very fast hyperparameter learning. The approach also allows for rigorous error analysis with Hilbert space theory, and we show that the approximation becomes exact when the size of the compact subset and the number of eigenfunctions go to infinity. We also show that the convergence rate of the truncation error is independent of the input dimensionality provided that the differentiability order of the covariance function increases appropriately, and for the squared exponential covariance function it is always bounded by \(∼ 1/m\) regardless of the input dimensionality. The expansion generalizes to Hilbert spaces with an inner product which is defined as an integral over a specified input density. The method is compared to previously proposed methods theoretically and through empirical tests with simulated and real data.

Cited by

Discussions

Related