

Hello all,
I am trying to analyze a Before-After Control-Impact experiment. However, my
model is not converging well and I am attempting to use a prior with parameter
expansion. I'm using count data (birds per point), well pad density per unit
area, and time (1=before, 2=after). 

prior<list(R=list(V=diag(1),nu=0.002),G=list(G1=list(V=diag(1),nu=0.002,alpha.mu=0,alpha.V=625),G2=list(V=diag(1),nu=0.002,alpha.mu=0,alpha.V=625),G3=list(V=diag(4),nu=0.002,alpha.mu=0,alpha.V=625)))
modelA<-MCMCglmm(Count~Density*Time,random=~ Block + Block:Point +idh(1+Density*Time):Species,family="poisson",pr=TRUE,prior=prior,data=edge,nitt=40000)
When trying to use the prior I get the following message:
Error in priorformat(if (NOpriorG) { :   V is the wrong dimension for some prior$G/prior$R elements
I realize that my V= value may be wrong but I'm unsure about what the value actually should be. Should I be using my covariance matrix?  Any help anyone could offer would be greatly appreciated. 
Thank you,
Nate Fronk
Penn State University

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