Laplace Approximation for Divisive Gaussian Processes for Nonstationary Regression
File(s)
Author(s)
Muñoz-González, L
Lázaro-Gredilla, M
Figueiras-Vidal, AR
Type
Journal Article
Abstract
The standard Gaussian Process regression (GP) is usually formulated under stationary hypotheses: The noise power is considered constant throughout the input space and the covariance of the prior distribution is typically modeled as depending only on the difference between input samples. These assumptions can be too restrictive and unrealistic for many real-world problems. Although nonstationarity can be achieved using specific covariance functions, they require a prior knowledge of the kind of nonstationarity, not available for most applications. In this paper we propose to use the Laplace approximation to make inference in a divisive GP model to perform nonstationary regression, including heteroscedastic noise cases. The log-concavity of the likelihood ensures a unimodal posterior and makes that the Laplace approximation converges to a unique maximum. The characteristics of the likelihood also allow to obtain accurate posterior approximations when compared to the Expectation Propagation (EP) approximations and the asymptotically exact posterior provided by a Markov Chain Monte Carlo implementation with Elliptical Slice Sampling (ESS), but at a reduced computational load with respect to both, EP and ESS.
Date Issued
2015-07-06
Date Acceptance
2015-06-25
Citation
IEEE transactions on Pattern Analysis and Machine Intelligence, 2015, 38 (3), pp.618-624
ISSN
2160-9292
Publisher
IEEE
Start Page
618
End Page
624
Journal / Book Title
IEEE transactions on Pattern Analysis and Machine Intelligence
Volume
38
Issue
3
Copyright Statement
© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Subjects
Artificial Intelligence & Image Processing
0801 Artificial Intelligence And Image Processing
0806 Information Systems
0906 Electrical And Electronic Engineering
Publication Status
Published