Hi all,
Stan-newbie here and I would appreciate any guidance for interpreting terms in a multinomial model. I am trying to regress a single covariate (FISH.TOTAL) on a cluster label outcome (3 clusters, cluster 1 is reference) with the model below:
def_priors <- c(
set_prior("normal(0, 10)", class = "b"),
set_prior("student_t(3,0,2.5)", class = "Intercept")
)
model.fish <- brm(data = data_diet,
family = categorical("logit",
refcat = 1),
cluster ~ FISH.TOTAL,
prior = def_prior)
Plotting out the posterior densities using mcmc_dens(), I get the plots below. My question is what is the difference between the intercept terms. It looks like for each of the non-reference clusters, there is a ‘b_mu2/3_Intercept’ and a ‘Intercept_mu2/3’. I would have thought there would be just one intercept for each cluster in relation to the reference. Any guidance would be much appreciated!
