I am using the Onion method for a problem I’ve previously posted about (e.g., Using the onion method in occupancy model hierarchical model - Modeling - The Stan Forums (mc-stan.org)).

Is it possible to encapsulate the “function” to be like the `lkj_corr_cholesky()`

function? I have created a simple function (here: stan_files/scale_cholesky_factor.stan · main · UMESC / quant-ecology / occStan_hm · GitLab (usgs.gov)) but there are still several calls outside of the function.

I would be willing to take a stab, but I cannot find the current `lkj_corr_cholesky()`

function in the GitHub page ( e.g., Search · lkj_corr_cholesky (github.com)). I am curious about how `lkj_corr_cholesky()`

handles probabilities.

In summary my two main questions:

- Where is the source code for
`lkj_corr_cholesky()`

? - How hard would it be to put the onion method into a function like
`lkj_corr_cholesky()`

?