Using at.level() with a MCMCglmm zero-inflated poisson model
I have a question for users of MCMCglmm that have experience implementing
the zero-inflated poisson model.
I find that the documentation, and previous questions, do not offer a lot
of clear guidance on specifying and interpreting the zipoisson model. In
particular, I see a lot of zero-inflated poisson examples that use the
at.level(trait, x):variableName syntax.
Specifically, the MCMCglmm course notes, available on the package's CRAN
page, uses the following example on page 102: