splitString <- function(text) {
  strings <- strsplit(text, " ")[[1]]
  newstring <- strings[1]
  linewidth <- stringWidth(newstring)
  gapwidth <- stringWidth(" ")
  availwidth <- 
    convertWidth(unit(1, "npc"), 
                 "inches", valueOnly=TRUE) 
  for (i in 2:length(strings)) {
    width <- stringWidth(strings[i])
    if (convertWidth(linewidth + gapwidth + width, 
                     "inches", valueOnly=TRUE) <
        availwidth) {
      sep <- " "
      linewidth <- linewidth + gapwidth + width
    } else {
      sep <- "\n"
      linewidth <- width
    }
    newstring <- paste(newstring, strings[i], sep=sep)
  }
  newstring
}