Get or Set the Stan Engine — mlumr

Control which Stan backend mlumr uses for model fitting. The default engine is "rstan" (compiled C++ models via rstantools). Users who prefer cmdstanr can switch engines after installation.

Usage

mlumr_engine(engine = NULL)

Arguments

engine: Character string: "rstan" or "cmdstanr". If NULL (default), returns the current engine without changing it.

Value

The current engine (character), returned invisibly when setting.

Details

When switching to "cmdstanr", this function checks whether the cmdstanr package and CmdStan toolchain are installed. If either is missing, it offers to install them interactively.

Engine names must be matched exactly. Partial strings such as "c" are not accepted.

The engine preference is stored as options(mlumr.stan_engine = ...) and persists for the current R session. To set a permanent default, add to your .Rprofile:

options(mlumr.stan_engine = "cmdstanr")

Examples

# Check current engine
mlumr_engine()
#> [1] "rstan"

# Switch to cmdstanr (interactive)
if (FALSE) { # \dontrun{
mlumr_engine("cmdstanr")
} # }