write_model.RdWrites a bi model to a file given by filename. The extension '.bi'
will be added if necessary.
write_model(x, filename)a stanedit object
name of the file to be written
the return value of the writeLines call.
model_file_name <- system.file(package = "stanedit", "regression.stan")
reg <- stanedit(filename = model_file_name)
new_file_name <- tempfile("reg", fileext = ".stan")
write_model(reg, new_file_name)