I am running a hurdle model using the glmmTMB function. My dependent variable is continuous and >= 0. I was looking for a function that would allow me to model the binary response in a logistic regression (i.e the zero inflated model) and the non-zero response in a Gamma (log) regression (i.e the conditional model). However, the glmmTMB function does not allow to use the gamma family.
I have two questions:
is there a function that allows to run a GLMM with gamma family? I tried to write my own code to have these two models but I am not sure about how to predict and calculate CIs.
Is it appropriate to use a truncated negative binomial family for the conditional (non-zero values) model? I ran the model:
hpm_nb <- glmmTMB(percapita_dia ~ Tipo_residuo + (1|Trip_ID), zi=~Tipo_residuo, all, family=truncated_nbinom2)
The diagnostics plots look good and model predictions are reasonable. Is it still wrong to have a truncated negative binomial family?