A function to create a regular grid over an observation window in order to model the spatial randome effects as a Gaussian Markov random field.
getgrd(shape, cellwidth)a SpatialPolygons object: the grid on which prediction of the spatial effects will occur
an object of class SpatialPolygons or SpatialPolygonsDataFrame
a scalar, the width of the grid cells
Benjamin M. Taylor and Barry S. Rowlingson (2017). spatsurv: An R Package for Bayesian Inference with Spatial Survival Models. Journal of Statistical Software, 77(4), 1-32, doi:10.18637/jss.v077.i04.
Finn Lindgren, Havard Rue, Johan Lindstrom. An explicit link between Gaussian fields and Gaussian Markov random fields: the stochastic partial differential equation approach. Journal of the Royal Statistical Society: Series B 73(4)