This function creates the precision matrix for the spatial prior based on thin-plate splines
and returns the matrix M, and its eigenvalues and eigenvectors
Usage
make.M(X, covariates)
Value
A list containing the precision matrix M and the object M.eigen containing
eigenvalues and eigenvectors for the matrix M.
Arguments
X
a matrix of spatial coordinates. It is recommended that the coordinates be scaled and centred.
covariates
the observed values for the covariates (including intercept).
Details
The M matrix is the precision matrix for the
spatial effects from the direct sampling spatial prior (DSSP) model. M is based on
thin plate splines basis functions, see White et. al. 2019 for more details on how the
matrix M is constructed.
## Use the Meuse River dataset from the package 'gstat'
library(sp)
library(gstat)
data(meuse.all)
coordinates(meuse.all) <- ~ x + y
X <- scale(coordinates(meuse.all))
make.M(X)