neighborhood graph with unconnected regions

[Marco Helbich]

Dear list,

I am running a Poisson model including a BYM latent Gaussian field. My neighborhood graph consists of different larger regions where only the areas within a specific region are connected but not the individual regions themselves. This results in the following warning: "graph for the model bym has XXX connected components!!! Model is revised accordingly." In which sense is the model revised? Should I and, if so, how can I account for the fact of non-connected regions?

Any hint is appreciated.

Best,
Marco

[Håvard Rue]

If the option adjust.for.con.comp=TRUE (default) then the model is
adjusted if the graph has more than one connected compoment. This
adjustment can be disabled setting this option to FALSE. If
adjust.for.con.comp=TRUE then constr=TRUE is interpreted as a sum-to-
zero constraint on EACH connected component in the graph and the
rankdef parameter is set to the number of connected components.


see inla.doc("besag")

Best
H
--
Håvard Rue
Department of Mathematical Sciences
Norwegian University of Science and Technology
N-7491 Trondheim, Norway
Voice: +47-7359-3533 URL : http://www.math.ntnu.no/~hrue
Mobile: +47-9260-0021 Email: havar...@math.ntnu.no

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