nsCrossdist

<code>nsCrossdist</code> calculates coordinate-specific cross distances in x, y,
and x-y for use in the nonstationary cross-correlation calculation. This
function is useful for calculating posterior predictions.

Enables off-the-shelf functionality for fully Bayesian, nonstationary Gaussian process modeling. The approach to nonstationary modeling involves a closed-form, convolution-based covariance function with spatially-varying parameters; these parameter processes can be specified either deterministically (using covariates or basis functions) or stochastically (using approximate Gaussian processes). Stationary Gaussian processes are a special case of our methodology, and we furthermore implement approximate Gaussian process inference to account for very large spatial data sets (Finley, et al (2017) <doi:10.48550/arXiv.1702.00434>). Bayesian inference is carried out using Markov chain Monte Carlo methods via the "nimble" package, and posterior prediction for the Gaussian process at unobserved locations is provided as a post-processing step.

Daniel Turek

BayesNSGP

Bayesian Analysis of Non-Stationary Gaussian Process Models

Mark Risser

nsCrossdist function

<dl><dt>coords</dt>
<dd>N x 2 matrix; contains x-y coordinates of station (observed)
locations.</dd>
<dt>Pcoords</dt>
<dd>M x 2 matrix; contains x-y coordinates of prediction
locations.</dd>
<dt>scale_factor</dt>
<dd>Scalar; optional argument for re-scaling the distances.</dd>
<dt>isotropic</dt>
<dd>Logical; indicates whether distances should be calculated
using Euclidean distance (<code>isotropic = TRUE</code>) or using the anisotropic
formulation (<code>isotropic = FALSE</code>).</dd></dl>

Arguments

Calculate coordinate-specific cross-distance matrices — nsCrossdist

<dl>

<dt>coords</dt>
<dd>N x 2 matrix; contains x-y coordinates of station (observed)
locations.</dd>


<dt>Pcoords</dt>
<dd>M x 2 matrix; contains x-y coordinates of prediction
locations.</dd>


<dt>scale_factor</dt>
<dd>Scalar; optional argument for re-scaling the distances.</dd>


<dt>isotropic</dt>
<dd>Logical; indicates whether distances should be calculated
using Euclidean distance (<code>isotropic = TRUE</code>) or using the anisotropic
formulation (<code>isotropic = FALSE</code>).</dd>

</dl>

nsCrossdist: Calculate coordinate-specific cross-distance matrices

Description

Usage

Value

Arguments

Examples