R/validate_arg_max_vif.R

In collinear: Automated Multicollinearity Management

#' Check and constrain argument \code{max_vif}
#'
#' @inheritParams collinear_select
#' @inheritParams validate_arg_quiet
#'
#' @return numeric or NULL
#' @autoglobal
#' @export
#' @family argument_validation
#' @examples
#' max_vif <- validate_arg_max_vif(
#'   max_vif = 11, #wrong value
#'   quiet = FALSE
#' )
#'
#' max_vif
#' attributes(max_vif)$validated
validate_arg_max_vif <- function(
  max_vif = NULL,
  quiet = FALSE,
  function_name = NULL
) {
  function_name <- validate_arg_function_name(
    default_name = "collinear::validate_arg_max_vif()",
    function_name = function_name
  )

  max_vif_default <- 5

  if (isTRUE(attr(x = max_vif, which = "validated"))) {
    return(max_vif)
  }

  if (is.null(max_vif)) {
    return(NULL)
  }

  if (is.numeric(max_vif)) {
    if (length(max_vif) > 1) {
      max_vif <- max_vif[1]

      if (quiet == FALSE) {
        message(
          "\n",
          function_name,
          ": argument 'max_vif' must be of length one, using value '",
          max_vif,
          "'."
        )
      }
    }
  } else {
    if (quiet == FALSE) {
      message(
        "\n",
        function_name,
        ": argument 'max_vif' is non-numeric, resetting it to to '",
        max_vif_default,
        "'."
      )
    }

    max_vif <- max_vif_default
  }

  if (max_vif > 10 || max_vif < 1) {
    if (quiet == FALSE) {
      message(
        "\n",
        function_name,
        ": argument 'max_vif' is outside its valid range (>=1 to <=10), resetting it to '",
        max_vif_default,
        "'."
      )
    }

    max_vif <- max_vif_default
  }

  attr(
    x = max_vif,
    which = "validated"
  ) <- TRUE

  max_vif
}