A Partial Warp Parameterization for the Spatial Deformation Model for Nonstationary Covariance

• Activity Number: 91
• Type: Invited
• Date/Time: Sunday, August 9, 2015 : 9:30 PM to 10:15 PM
• Sponsor: Section on Statistics and the Environment
• Author(s): Paul D. Sampson*
• Companies: University of Washington
• Keywords: Nonstationary covariance ; Spatial deformation ; Thin-plate spline ; Partial warps ; Dimension reduction

Abstract

The spatial deformation model introduced by Sampson and Guttorp has been around for a long time, but it (and most of the other modeling strategies for nonstationary covariance) have suffered from a lack of flexible and convenient software. A simple reparameterization in terms of partial warps of the thin-plate spline approach to spatial deformations provides a convenient framework for more efficient numerical estimation, strategies for dimension reduction, and application to larger problems than has been practical. We explain the nature of the partial warp decomposition of splines and present preliminary illustrations of the fitting of deformations for simulated spatio-temporal and spatial datasets. We note a number of research directions and extensions for this work in progress.