It computes the spatial covariance and precision matrix of the neighboring subregions using Intrinsice Autoregressive Conditional (ICAR) process.
buildH(areapoly, permutation = NA)
A list of two matrices: Precision matrix H and the covariance matrix obtained through Moore-Penrose inverse of H.
The polygon of the areas. We can obtain this through readOGR
function from sp
matrix.
Permutation order of the subregions
The off-digonal values are -1 when two subregions are neighbors. Otherwise, we assign 0. The diagonal values are the sum of the values of its own row.