# Analysis API

#41

Yes.

• in RStan and PyStan: the draws of parameters within a chain is a contiguous block of memory that can be accessed with double* (see @ariddell’s comment)
• RStan and PyStan are able to handle exceptions (@ariddell’s comment), but this may not be the best way to handle output (@betanalpha’s comment)
• this was the proposed \hat{R} function signature (for a single parameter):
• @betancourt is proposing a parallel set of functions for checking diagnostics that returns a boolean and optionally passes a std::string message to a writer:

#42

#43

It’s pretty much either src/stan/analyze/mcmc or src/stan/mcmc/analyze. I’m OK either way. Here’s what’s there now:

ls src/stan/
callbacks/    io/           mcmc/         optimization/ variational/
command/      lang/         model/        services/     version.hpp


Will there also be services methods for these?

#44

I think we were all thinking these were the service methods, but I could be mistaken.