R/reorder.R

In gdata: Various R Programming Tools for Data Manipulation

reorder.factor <- function(x, X, FUN, ..., order=is.ordered(x), new.order,
                           sort=mixedsort)
{
  constructor <- if (order) ordered else factor

  if(!missing(X) || !missing(FUN))
  {
    if(missing(FUN)) FUN <- 'mean'

    ## I would prefer to call stats::reorder.default directly,
    ## but it is not exported from stats, so the relevant code is
    ## replicated here:
    ## -->
    scores <- tapply(X = X, INDEX = x, FUN = FUN, ...)
    levels <- names(base::sort(scores, na.last = TRUE))
    if(order)
      ans <- ordered(x, levels=levels)
    else
      ans <- factor(x, levels=levels)
    attr(ans, "scores") <- scores
    ## <--
    return(ans)
  }
  else if (!missing(new.order))
  {
    if (is.numeric(new.order))
      new.order <- levels(x)[new.order]
    else
      new.order <- new.order
  }
  else
    new.order <- sort(levels(x))

  constructor(x, levels=new.order)
}