Right now
posterior_predictiveis trying to do way too much I think. We should have a function with another name for computing expressions based on variables in a trace.
Yes, I can agree with that. There are cases where one wants to know the proper posterior predictive sampling to be compared with obs, and cases where one simply need to calculate stuff with the model.
About var_names and posterior_predictive_sampling, it’s enough to know it. I went back and figured that what I called “breaking” behaviour already occured in v4, and I had to come back to v3 to see the deterministic behaviour (everything seen in the trace is not resampled). I certainly see powerful uses of it, and at times I needed such behaviour but misunderstood the use of posterior_predictive_sampling. Anyway, thanks for clarifying once more.