Stanc optimization and generated quantities

Developers
1

I recently realized that in my setup (Mac OS X 26.1 on an M1 Macbook pro, using cmdstan 2.37) I was not giving the optimization flag to stanc. So I changed that option. And immediately my “generated quantities” runs became hugely slow: things which had taken a few seconds instead took tens of minutes. The modeling runs were unaffected (or maybe faster?).

I’d be happy to test it on a reproducible setup. My current code is…not that. Is one of the examples or a common test well set up to test this workflow?

2

That’s very interesting. I would not expect it to make any difference in the standalone generated quantities case, as most of the optimizations are around autodiff

Any code you can share would be useful!