Computer emulation with non-stationary Gaussian processes

Journal Article

Gaussian process (GP) models are widely used to emulate propagation uncertainty in computer experiments. GP emulation sits comfortably within an analytically tractable Bayesian framework. Apart from propagating uncertainty of the input variables, a GP emulator trained on finitely many runs of the experiment also offers error bars for response surface estimates at unseen input values. This helps select future input values where the experiment should be run to minimize the uncertainty in the response surface estimation. However, traditional GP emulators use stationary covariance functions, which perform poorly and lead to suboptimal selection of future input points when the response surface has sharp local features, such as a jump discontinuity or an isolated tall peak. We propose an easily implemented nonstationary GP emulator, based on two stationary GPs, one nested into the other, and demonstrate its superior ability in handling local features and selecting future input points from the boundaries of such features.

Full Text

Duke Authors

Cited Authors

  • Montagna, S; Tokdar, ST

Published Date

  • 2016

Published In

  • Siam/Asa Journal of Uncertainty Quantification

Volume / Issue

  • 4 /

Start / End Page

  • 26 - 47

Pages

  • 22