


Hi,
I've got a model that I've been working on in MCMCglmm.  I asked some questions about this model on the list before but I'm still wrestling with a problem.  Initially I used the model below which has a random effect of individual and pack (social group).  Road is a continuous variable.  This allowed me to estimate a separate slope for the effect of road for each individual and the results made sense.  
Model1<-MCMCglmm(used~X1+X2+X3,random=~us(1+road):individual+pack,family="categorical", data=datum,prior=prior1,pr=TRUE)
Here's the prior I'm using:
prior1<-list(R=list(V=1,fix=1),G = list(G1 = list(V = diag(2), nu = 1.002),G2 = list(V = 1, nu = 0.002)))
Now I'd like to extend this by looking at the effect of road for each individual by seeing how that might differ between day and night (categorical variable ("day"), 1 = day, 0 = night).  To goal is to derive a coefficient for the effect of the difference in use of roads between day and night for each individual.
I have 2 questions:
1. What would the coding be for the random effect... I'm thinking something like:
random~us(road:day):individual + pack or random~us(1+road:day):individual+pack
2. How to modify my prior above for the new matrix with the road x day x individual interaction?  
I would be grateful for any help with this problem. Please let me know if anyone has ideas.
Thanks!
John
 		 	   		  
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