Closed
Description
I noticed that the results of pm.sample_posterior_predictive
are flattened over (chain, draw) dimensions. AFAIK, this is a lossy transform because the results are numpy objects that don't track the source. I wonder if there should be an option to preserve the (chain, draw) shape and output the results using an arviz InferenceData object. See also arviz-devs/arviz#1282