R/helpers_knitr.R

In Roche/crmPack: Object-Oriented Implementation of CRM Designs

#' Check That Labels Are Valid and Useful
#'
#' A vector of labels is valid and useful if it is of length 2, of type character
#' and its values are distinct.
#'
#' If `x` is a scalar, a second element is added, whose value is the value of the
#' scalar with "s" appended.  If `x` is `"toxicity"`, the plural is handled appropriately.
#'
#' @param x (`character`)\cr The vector to be checked
#' @keywords internal
#' @return a character vector of length 2 whose values are distinct
h_prepare_labels <- function(x) {
  assert_character(x, min.len = 1, max.len = 2, any.missing = FALSE, unique = TRUE)

  if (length(x) == 1) {
    if (x == "toxicity") {
      x <- c("toxicity", "toxicities")
    } else {
      x[2] <- paste0(x[1], "s")
    }
  }
  x
}

#' Append Units to a Numeric Dose
#'
#' @param units (`character`)\cr the units to be displayed
#' @keywords internal
#' @return if `units` is `NA`, then `NA`.  Otherwise, `units`, ensuring that exactly
#' one space precedes the first non-whitespace character
h_prepare_units <- function(units = NA) {
  assert_character(units, len = 1)

  ifelse(
    is.na(units),
    "",
    paste0(" ", stringr::str_trim(units, "left"))
  )
}