R/format_num.R

In moj-analytical-services/mojrap: Generic Functions for Reproducible Analytical Pipelines in MoJ

#' Format numbers with commas
#'
#' Formats numbers with thousand delimited commas. Values of less than 10 are represented as words by default.
#'
#' @param number A number.
#' @param less_than_10_as_words A logical determining whether values less than 10 are represented as words.
#'
#' @return A character object.
#'
#' @examples
#' format_num("1000") # returns "1,000"
#' format_num("1") # returns 'one'
#' format_num("7", less_than_10_as_words = FALSE) # returns "7"
#' @export

format_num <- function(number, less_than_10_as_words = TRUE) {

  tryCatch({

    # Checks on input

    # Check that only one value is passed to format_perc() at a time and raise
    # an error otherwise.

    if (length(number) > 1) {

      stop(
        "Input to format_num is not a single value. ",
        "Most likely you have tried to pass a vector, ",
        "list, or df to format_num()",
        call. = FALSE
      )

    } else if  (is.null(number)) {

      # Check that number is not null, and raise an error if it is

      stop("Input to number_perc is NULL", call. = FALSE)

    } else if (is.na(number)) {

      # Check that number is not null, and raise and error if it is

      stop("Input to number_perc is NA", call. = FALSE)

    } else if (!less_than_10_as_words %in% c(TRUE, FALSE)) {

      stop("less_than_10_as_words must be either TRUE or FALSE", call. = FALSE)

    } else {

### MAIN BODY ------------------------------------------------------------

      # If checks of function pass, then run the main body of the function, and
      # return and numberput.

      number <- formatC(abs(as.numeric(number)),
                     big.mark = ",", digits = 0, format = "d")

      if (less_than_10_as_words == TRUE){

        if (mojrap::as_number(number) == 1) {
          number <- "one"
        }
        else  if (mojrap::as_number(number) == 2) {
          number <- "two"
        }
        else  if (mojrap::as_number(number) == 3) {
          number <- "three"
        }
        else  if (mojrap::as_number(number) == 4) {
          number <- "four"
        }
        else  if (mojrap::as_number(number) == 5) {
          number <- "five"
        }
        else  if (mojrap::as_number(number) == 6) {
          number <- "six"
        }
        else  if (mojrap::as_number(number) == 7) {
          number <- "seven"
        }
        else  if (mojrap::as_number(number) == 8) {
          number <- "eight"
        }
        else  if (mojrap::as_number(number) == 9) {
          number <- "nine"
        }
        else number

      }

      return(number)
    }


  })

}