I sample my model with two chains and 600 draws each. Then I sample the posterior predictive, using pm.sample_posterior_predictive() (or its speedy cousin pm.fast_sample_posterior_predictive()). The posterior predictive dataset has one chain and 1200 draws. Why does sampling the posterior predicti…

Is there a return_inferencedata argument to sample_posterior_predictive? We have had some issues retrieving the original shape due to this internal reshaping when sampling the posterior predictive. Here it looks like it is ignoring the info in the provided trace (or posterior dataset) and independen…

Why does sample_posterior_predictive use only one chain?

Questions

rpgoldman October 27, 2020, 10:26pm 16

I can replicate this error. I will see if I can track it down.

2 Likes

Topic		Replies	Views
Number of samples generated by `sample_posterior_predictive` Questions	3	1097	October 7, 2020
Sample_posterior_predictive Questions	1	924	May 2, 2019
ValueError: conflicting sizes for dimension 'chain': length 1 on the data but length 2 on coordinate 'chain' v5	8	1703	October 13, 2022
Understanding shape of values returned by sample_posterior_predictive Questions	3	914	January 26, 2020
Example for out-of-sample prediction with posterior predictive sampling v5	8	3314	October 28, 2022

Why does sample_posterior_predictive use only one chain?

Related topics