man-roxygen/return-conv.R

In stan-dev/posterior: Tools for Working with Posterior Distributions

#' @return
#' If the input is an array, returns a single numeric value. If any of the draws
#' is non-finite, that is, `NA`, `NaN`, `Inf`, or `-Inf`, the returned output
#' will be (numeric) `NA`. Also, if all draws within any of the chains of a
#' variable are the same (constant), the returned output will be (numeric) `NA`
#' as well. The reason for the latter is that, for constant draws, we cannot
#' distinguish between variables that are supposed to be constant (e.g., a
#' diagonal element of a correlation matrix is always 1) or variables that just
#' happened to be constant because of a failure of convergence or other problems
#' in the sampling process.
#'
#' If the input is an [`rvar`], returns an array of the same dimensions as the
#' [`rvar`], where each element is equal to the value that would be returned by
#' passing the draws array for that element of the [`rvar`] to this function.