Methods a ported brms script may call that frmtmb does not have

These brmsfit methods either describe machinery frmtmb does not use (Stan code and Stan data) or are brms spellings that have been renamed. They are defined so that a ported script gets the reason and the replacement rather than "could not find function", which is what the vignette-port audit measured most of its post-processing failures as.

Usage

# S3 method for class 'frmtmb_draws'
stancode(object, ...)

# S3 method for class 'frmtmb_draws'
standata(object, ...)

# S3 method for class 'frmtmb_draws'
expose_functions(x, ...)

restructure(x, ...)

# S3 method for class 'frmtmb_draws'
restructure(x, ...)

Arguments

object, x, ...

Ignored; these functions always stop.

Value

These functions never return; they signal an error.

Examples

# \donttest{
if (requireNamespace("tmbstan", quietly = TRUE) &&
    requireNamespace("rstan", quietly = TRUE) &&
    !frmtmb.sample:::tmbstan_build_broken()) {
  set.seed(1)
  dd <- data.frame(x = rnorm(40))
  dd$y <- rnorm(40, 1 + 0.5 * dd$x, 1)
  fit <- frm(bf(y ~ x), family = gaussian(), data = dd)
  ds <- frm_sample(fit, chains = 1, iter = 400, refresh = 0)
  # each refusal names its reason and the replacement
  try(stancode(ds))
  try(standata(ds))
}
#> frm_sample(): default priors (brms 2.23 defaults; prior = "flat" puts brms's (flat) in every slot)
#>   Intercept          student_t(3, 1.1, 2.5)
#>   sigma              student_t(3, 0, 2.5)  [natural scale]
#>   b                  (flat), as brms leaves slopes
#> Error : stancode() has no meaning for frmtmb: there is no Stan program. The model is an R closure built by build_objective() from the assembled frame and differentiated by RTMB, and the closure IS the source: print `ds$fit$obj$fn` for the evaluator and `ds$fit$frame` for everything baked into it
#> Error : standata() has no meaning for frmtmb: nothing is exported to a Stan data list. The assembled frame `ds$fit$frame` holds the same content (the response, the design matrices, the sparse Z, the addition terms), and model.matrix(), getME() and model.frame() read the pieces of it individually
# }