R/fill.R

In LW1949: An Automated Approach to Evaluating Dose-Effect Experiments Following Litchfield and Wilcoxon (1949)

#' Fill in Missing Values
#'
#' Fill in missing values in a vector, using the last recorded value.
#' @param x
#'   A vector, can be character, numeric, or logical.
#' @param resetWhen
#'   A logical vector, the same length as \code{x}, indicating elements that
#'   should not be filled in.
#' @return
#'   A vector the same length as \code{x}, with all NAs or ""s replaced by
#'   the last value for the vector.
#'   Note that and missing values at the beginning of the vector will not
#'   be replaced.
#' @export
#' @details
#'   Similar to \code{\link[zoo]{na.locf}} in the \code{zoo} package,
#'   but works for "" in character vectors as well.
#' @examples
#' numvec <- c(NA, 1:5, NA, NA, NA, 10:12, NA)
#' newgroup <- c(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0)
#' fill(numvec)
#' fill(numvec, newgroup)
#'
#' charvec <- c("", letters[1:5], "", "", "", letters[10:12], "")
#' fill(charvec)

fill <- function(x, resetWhen=rep(FALSE, length(x))) {
  # fill in a vector of values
  # assign to every NA or "" the last value for the vector
  y <- x
  last <- x[1]
  if (is.character(x)){
    for(i in 2:length(x)) {
      if ((x[i]=="" | is.na(x[i])) & !resetWhen[i]) {
        y[i] <- last
      } else {
        last <- x[i]
      }
    }
  } else {
    for(i in 2:length(x)) {
      if (is.na(x[i]) & !resetWhen[i]) {
        y[i] <- last
      } else {
        last <- x[i]
      }
    }
  }
  y
}