[R] excluding models during dredge and model averaging in MuMIn

[Andrew MacIntosh]

Dear R Users,

I am using the package "MuMIn" to sort through models, with the goal
of estimating parameters through model averaging of the candidate set.
I have been using the dredge function to build all possible models
based on my starting point (hypothetical global model). I see that
there is a simple way to control which models are excluded from this
set...

# exclude models containing both X1 and X2
>dredge(x, subset = !(X1 & X2))

However, I would like to add to this and exclude 4 different
combinations of predictors (i.e. X1&X2, X1&X3, X2&X3, X1&X2&X3).

I would very much appreciate it if somebody had any ideas about how to
tackle this. Also,

Cheers,
Andrew

Andrew JJ MacIntosh, D. Sc.
Center for International Collaboration and
Advanced Studies in Primatology
Kyoto University Primate Research Institute
Kanrin 41-2 Inuyama Aichi Japan 484-8506
website: http://www.wix.com/andyjmac/andrew-macintosh