Re: [R] MCMCglmm heteroscedasticity dependent on predictor

2011-09-15 Thread Ben Bolker
Atle Torvik Kristiansen gmail.com> writes: > I have a dataset where the residual variance decreases with on one of > the predictors (population size). > > Currently, the full model looks like this: > > prior<-list(R=list(V=1e-16, nu=-2),G1=list(V=diag(2), nu=2)) > > m<-MCMCglmm(response~poly(p

[R] MCMCglmm heteroscedasticity dependent on predictor

2011-09-15 Thread Atle Torvik Kristiansen
Hi, I have a dataset where the residual variance decreases with on one of the predictors (population size). Currently, the full model looks like this: prior<-list(R=list(V=1e-16, nu=-2),G1=list(V=diag(2), nu=2)) m<-MCMCglmm(response~poly(population size,2)*poly(other predictor,2)+time, random=~