Regarding prediction/posterior_epred/posterior_predict from brms ordinal model

[torkar]

Hi, I found this reply to help many people understanding the three posterior functions commonly used:

Reproduce posterior_predict from posterior_linpred for a neg binom spline model

Hi Angelo, here’s a brief explanation of the difference. Suppose you have a negative binomial regression with a log link: \eta_i = a + bx_i \\ \lambda_i = \exp(\eta_i) \\ y_i \sim {\rm NegBinom}(\lambda_i, \phi) posterior_linpred() gives you posterior draws of \eta. posterior_linpred(transform=TRUE), or equivalently posterior_epred(), gives you posterior draws of \lambda, that is, it does the inverse link transformation for you. posterior_predict() gives you draws from {\rm NegBinom}(\l…