R/check_controls.R

In loelschlaeger/vntrs: Variable Neighborhood Trust Region Search

#' Check controls
#'
#' @description
#' This function checks the input \code{controls}.
#'
#' @param controls
#' Either \code{NULL} or a named list with the following elements. Missing
#' elements are set to the default values in parentheses.
#' \itemize{
#'   \item \code{init_runs} (\code{5}):
#'   The number of initial searches.
#'   \item \code{init_min} (\code{-1}):
#'   The minimum argument value for the random initialization.
#'   \item \code{init_max} (\code{1}):
#'   The maximum argument value for the random initialization.
#'   \item \code{init_iterlim} (\code{20}):
#'   The number of iterations for the initial searches.
#'   \item \code{neighborhoods} (\code{5}):
#'   The number of nested neighborhoods.
#'   \item \code{neighbors} (\code{5}):
#'   The number of neighbors in each neighborhood.
#'   \item \code{beta} (\code{0.05}):
#'   A non-negative weight factor to account for the function's curvature in the
#'   selection of the neighbors. If \code{beta = 0}, the curvature is ignored.
#'   The higher the value, the higher the probability of selecting a neighbor in
#'   the direction of the highest function curvature.
#'   \item \code{iterlim} (\code{1000}):
#'   The maximum number of iterations to be performed before the local search is
#'   terminated.
#'   \item \code{tolerance} (\code{1e-6}):
#'   A positive scalar giving the tolerance for comparing different optimal
#'   arguments for equality.
#'   \item \code{time_limit} (\code{NULL}):
#'   The time limit in seconds for the algorithm.
#' }
#'
#' @return
#' The checked and filled list \code{controls}.
#'
#' @export

check_controls <- function(controls) {
  if (is.null(controls)) {
    controls <- list()
  }
  if (!is.list(controls)) {
    stop("'controls' must be a list.",
      call. = FALSE
    )
  }
  if (is.null(controls[["init_runs"]])) {
    controls[["init_runs"]] <- 5
  }
  if (!(is.numeric(controls[["init_runs"]]) && controls[["init_runs"]] > 0 &&
    controls[["init_runs"]] %% 1 == 0)) {
    stop("'controls$init_runs' must be a positive number.",
      call. = FALSE
    )
  }
  if (is.null(controls[["init_min"]])) {
    controls[["init_min"]] <- -1
  }
  if (!is.numeric(controls[["init_min"]])) {
    stop("'controls$init_min' must be a numeric.",
      call. = FALSE
    )
  }
  if (is.null(controls[["init_max"]])) {
    controls[["init_max"]] <- 1
  }
  if (!is.numeric(controls[["init_max"]])) {
    stop("'controls$init_max' must be a numeric.",
      call. = FALSE
    )
  }
  if (controls[["init_max"]] < controls[["init_min"]]) {
    stop("'controls$init_max' must not be smaller than controls$init_min.",
      call. = FALSE
    )
  }
  if (is.null(controls[["init_iterlim"]])) {
    controls[["init_iterlim"]] <- 20
  }
  if (!is.numeric(controls[["init_iterlim"]])) {
    stop("'controls$init_iterlim' must be a numeric.",
      call. = FALSE
    )
  }
  if (is.null(controls[["neighborhoods"]])) {
    controls[["neighborhoods"]] <- 5
  }
  if (!(is.numeric(controls[["neighborhoods"]]) &&
    controls[["neighborhoods"]] > 0 && controls[["neighborhoods"]] %% 1 == 0)) {
    stop("'controls$neighborhoods' must be a positive number.",
      call. = FALSE
    )
  }
  if (is.null(controls[["neighbors"]])) {
    controls[["neighbors"]] <- 5
  }
  if (!(is.numeric(controls[["neighbors"]]) &&
    controls[["neighbors"]] > 0 && controls[["neighbors"]] %% 1 == 0)) {
    stop("'controls$neighbors' must be a positive number.",
      call. = FALSE
    )
  }
  if (is.null(controls[["beta"]])) {
    controls[["beta"]] <- 0.05
  }
  if (!(is.numeric(controls[["beta"]]) && controls[["beta"]] >= 0)) {
    stop("'controls$beta' must be greater zero.",
      call. = FALSE
    )
  }
  if (is.null(controls[["iterlim"]])) {
    controls[["iterlim"]] <- 1000
  }
  if (!is.numeric(controls[["iterlim"]])) {
    stop("'controls$iterlim' must be a numeric.",
      call. = FALSE
    )
  }
  if (is.null(controls[["tolerance"]])) {
    controls[["tolerance"]] <- 1e-6
  }
  if (!(is.numeric(controls[["tolerance"]]) && controls[["tolerance"]] >= 0)) {
    stop("'controls$tolerance' must be non-negative.",
      call. = FALSE
    )
  }
  if (!is.null(controls[["time_limit"]])) {
    if (!is.numeric(controls[["time_limit"]])) {
      stop("'controls$time_limit' must be a numeric.",
        call. = FALSE
      )
    }
  }
  return(controls)
}