Validate a user-defined epidemic process for RTMB traceability — validate_custom

Usage

validate_custom_epidemic(epidemic, test_theta = NULL)

Arguments

epidemic: A custom_epidemic_class object from custom_epidemic().
test_theta: Optional numeric vector of length n_params to use as the test point. Defaults to epidemic@inits.

Value

epidemic, invisibly. Emits a success message if the check passes.

Details

Passes intensity_fn through RTMB::MakeADFun at the supplied (or default) initial values and confirms that the objective value and gradient are both finite. Emits an informative error if the function is not AD-safe.

Examples

# Custom components tape USER functions, so RTMB must be attached
# (it is kept in Imports, not Depends, so attach it yourself):
library(RTMB)
max_time <- 15L
rw_fn <- function(theta)
  matrix(theta[1] + cumsum(exp(theta[2]) * theta[3:(2L + max_time)]), max_time, 1L)
custom_epi <- custom_epidemic(
  rw_fn,
  priors = c(list(normal_prior(2, 1), normal_prior(-2, 0.5)),
             rep(list(std_normal_prior()), max_time)),
  inits  = c(2, -2, rep(0, max_time))
)
validate_custom_epidemic(custom_epi)
#> ✔ Custom epidemic `Custom` passes RTMB traceability check.