R/coerce_NA_text.R

In mjdufort/miscHelpers: Miscellaneous helper functions

#' Coerce textual NAs to true NA values
#'
#' This function is designed to convert textual NAs to true NA values. It can operate on vectors, data
#' frames, data frame like objects (e.g. tibbles), or matrices. It returns an object of the same class.
#' The values that will be coerced to NAs can be provided as a character vector.
#' @param x vector, matrix, or data frame containing the data to be coerced
#' @param NA_values character vector, the values to be coerced to NAs.
#' @param add_NA_values character vector, additional values (beyond \code{NA_values}) to coerce to NA. This argument simplifies keeping the default \code{NA_values} and adding one or more additional values to it
#' @param verbose logical, whether to output information on data being coerced; if \code{x} is a data frame, the function will output the names of the columns with data being coerced.
#' @export
#' @return An object of the same type as the input data
#' @usage coerce_NA_text(
#'   x, NA_values = c("NA", "na", "N/A", "n/a", "", "."), 
#'   add_NA_values, verbose = FALSE)

coerce_NA_text <- 
  function(x, NA_values = c("NA", "na", "N/A", "n/a", "", "."), 
           add_NA_values = NULL, verbose = FALSE) {
    if (!is.null(add_NA_values)) NA_values <- union(NA_values, add_NA_values)
    if (is.vector(x) | is.matrix(x)) {
      x[x %in% NA_values] <- NA
    } else if (inherits(x, "data.frame")) {
      for (col.tmp in 1:ncol(x))
        if (any(x[[col.tmp]] %in% NA_values)) {
          x[[col.tmp]][x[[col.tmp]] %in% NA_values] <- NA
          if (verbose) print(paste("Coerced textual NAs to true NAs for column", colnames(x)[col.tmp]))
        }
    } else stop("Input data object must be a vector, data frame")
    x
  }