Full forward sampling of a brms model's responses for a SINGLE posterior draw

Simulates the response(s) of a brmsfit at a single posterior draw, respecting dependency order among multiple responses. Ported from the SBC package and the 0.x bayesim codebase; bayeshear/SBC/future dependencies removed.

Usage

brms_full_ppred(fit, newdata = NULL, draw = 1L)

Arguments

fit

A brmsfit with posterior draws.

newdata

Optional data.frame of predictors. If NULL, uses fit$data.

draw

Single integer draw index to simulate.

Value

A data.frame (a copy of newdata) with the simulated response column(s) filled in.

Details

ifs_generator() only ever needs one draw per task (the deterministic rep_idx-indexed draw), so this function takes a single draw index and returns a single data.frame. This eliminates the prior index mismatch where results were stored at pp_data[[draw_value]] but read at simulated[[1]].