Spatial models

GLMM’s on large spatial grids — by Hans Julius Skaug — last modified Jan 12, 2010 01:43 PM

It has for a long time been possible to fit GLMMs (Generalized Linear Mixed Models) in ADMB-RE. A typical example is correlated count data with Poisson distribution. However, when the observation are located on a spatial grid the number of latent variables (random effects in the ADMB-RE terminology) grows quadratically in the number of grid points in each geographical direction. The large number of random effects causes a computational challenge.

Poisson GLMM (irregular grid) — by Hans Julius Skaug — last modified Mar 30, 2010 10:57 PM

GLMM with spatial correlation, where the locations do not lie on a grid. Illustrates how you can parameterize a large correlation matrix in terms of an isotropic correlation function r(d), where "d" is the distiance between two locations.