[R] question regarding the AICcmodavg package

[Hannah van Noort]

Dear moderator,

If possible I would like to send in the following question for R-help:

I am analyzing a small data set using PGLS with phylogenetic uncertainty
taken into account and thereby including 100 potential phylogenetic tree
scenarios. I've managed to run models on all of the different trees and
performed model averaging to get parameter estimates for the intercept and
most of the predictor variable slopes using the *AICcmodavg* package and
*APE*, but I seem to get stuck with some of the variables that are also
included in a two-way interaction in the model. I can obtain values for the
two-way interaction but not for the variables separately.

The error I receive is:

“Error in modavg.AICgls(parm = "agefirstbreed", cand.set = Cand.models4, :

Some models include more than one instance of the parameter of interest.
This may be due to the presence of interaction/polynomial terms, or
variables with similar names: see "?modavg" for details on variable
specification and "exclude" argument”



I'm familiar with the *exclude* function of the *AICcmodavg* package, but
this only works when different models have been specified including ones
without these specific two-way interactions and my models are all similar
with regards to the interactions, only the phylogenetic tree scenarios
differ.



I was wondering if there is another method to obtain these averaged
parameter estimates for the concerning predictor variable slopes? Not
excluding the (significant) two-way interaction in which they are also
involved?
Thank you in advance for your reply.

Kind regards,

Hannah van Noort

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