frmtmb.spatial

Spatial random fields for frmtmb models. The package registers its fields with frmtmb through the public covariance-structure seam, frmtmb::frmtmb_register_covstruct().

• car(M, gr = g, type = ): brms’s conditional autoregressive field over an adjacency matrix, in its four types.
• spde(fem, gr = node): a Matern field over a finite-element mesh, from the mesh’s three matrices (fmesher::fm_fem()).
• sar(M, type = ): brms’s simultaneous autoregressive term, in its lag and error forms, registered through the residual correlation seam, frmtmb::frmtmb_register_autocor().

Installation

frmtmb.spatial lives in the extensions/ directory of the frmtmb repository. Install frmtmb first, then this package:

remotes::install_github("aforren1/frmtmb")
remotes::install_github("aforren1/frmtmb", subdir = "extensions/frmtmb.spatial")

Use

library(frmtmb.spatial)
fit <- frm(bf(y ~ x + car(W, gr = loc, type = "icar")),
           family = gaussian(), data = d, data2 = list(W = W))
confint_varcorr(fit)

Without the package loaded, frm() refuses car(), spde() and sar() and names this package. vignette("spatial", package = "frmtmb.spatial") covers all three.