cmdstanR: writing to rdump

I’ve been really enjoying making the move over from rstan to cmdstanr, but was surprised when I discovered from the cmdstanr guidance that to fit models using data in rdump files, you need to first create these using rstan::stan_rdump.

Is this a long term dependency (eg. for design or technical reasons?) or simply something that hasn’t been implemented yet?



its not required to use rdump to fit models. Cmdstanr stores the data in the JSON format and then fits the model with the JSON temporary file.

The note on rdump files is if you wish to explicitly use the rdump format to run cmdstan. We advise you to use JSON as cmdstan input with JSON is faster than rdump.

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Thanks for the really fast reply - and for pointing me towards using json instead!