Missing von Mises distribution in brms 2.22.0?

Interfaces brms
1

I just updated my brms version to 2.22.0, and am now getting an error message when trying to fit a von Mises model to some data. The message is as follows:

In file(con, “r”) :
cannot open file ‘/Library/Frameworks/R.framework/Versions/4.3-arm64/Resources/library/brms/chunks/fun_von_mises.stan’: No such file or directory

I’ve checked the directory itself, and sure enough, whereas all the other distribution functions are there, the von Mises one is missing. The model was working 5 minutes ago before I updated brms, and I’m not having the same issue if I fit the data with a Gaussian model, so I strongly suspect the updated version is to blame. Nonetheless, if anyone else has come across this error and/or can identify another reason it’s occurring, I’d appreciate hearing about it.

2

Some github sleuthing reveals that file was removed in this change: use von_mises_lpdf directly instead of von_mises2_lpdf after next stan update · Issue #1633 · paul-buerkner/brms · GitHub

The bug you are seeing appears to have been fixed: remove outdated include statement by venpopov · Pull Request #1678 · paul-buerkner/brms · GitHub

Perhaps you can try installing the github version, and if that doesn’t work report your issue there.

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3

Thanks for the sleuthing. The version on github still gives the same error, unfortunately, so I’ll report the bug.

4

For anyone reading this later, it was not an issue with brms itself, but rather (as I understand it) some holdover code from an old version still being attached to models I was then fitting with a new version.

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