R/check_delta.R

In Weiming-Hu/EITrans: Empirical Inverse Transform Function for Ensemble Calibration

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# Author: Weiming Hu <weiming@psu.edu>
#         Geoinformatics and Earth Observation Laboratory (http://geolab.psu.edu)
#         Department of Geography and Institute for CyberScience
#         The Pennsylvania State University
#

#' EITrans::check_delta
#'
#' EITrans::check_delta checks whether the left/right deltas are valid EITrans arguments.
#'
#' @author Weiming Hu <weiming@@psu.edu>
#'
#' @param left_delta A left-edge delta value to validate
#' @param left_delta A left-edge delta value to validate
#' @param num_members The number of ensemble members
#' @return NULL if validate; otherwise an error will be raised.
#'
#' @md
#' @export
check_delta <- function(left_delta, right_delta, num_members) {
  sample <- seq(0 + left_delta, 1 + right_delta, length.out =  num_members + 2)
  sample <- sample[2:(num_members+1)]

  if (any(sample <= 0) | any(sample >= 1)) {
    msg <- paste0('[', left_delta, ', ', 1 + right_delta, '] with ', num_members,
                  ' members leads to out-of-boundary values [',
                  paste(range(sample), collapse = ','), ']')
    stop(msg)
  }
}