Fit Centroid MVN Small Area Estimation model using TMB.
fck_tmb.RdRandom effects have a multivariate Gaussian distribution with covariance
matrix calculated using centroid_covariance. Kernel hyper-parameters
are fixed.
TMB.fck_tmb.RdRandom effects have a multivariate Gaussian distribution with covariance
matrix calculated using centroid_covariance. Kernel hyper-parameters
are fixed.