R/makePaperCloud.R

In muschellij2/googleCite: Google Citation

#' @name makePaperCloud
#' @title Paper Cloud Maker
#' @description Make word cloud of papers
#' @param tab Table generated by googleCite
#' @param addstopwords words to remove
#' @param ... Not currently used.
#' @return NULL (Plot rendered)
#' @export

makePaperCloud <- function(tab, addstopwords=NULL, ...) {

  colIndex = which(names(tab) == "Title")
  
  corpus <- Corpus(DataframeSource(data.frame(tab[, colIndex])))
  corpus <- tm_map(corpus, removePunctuation)
  corpus <- tm_map(corpus, content_transformer(tolower))
  corpus <- tm_map(corpus, function(x) removeWords(x, stopwords("english")))
  if (!is.null(addstopwords)) corpus <- tm_map(corpus, function(x) 
    removeWords(x, addstopwords))
  
  tdm <- TermDocumentMatrix(corpus)
  m <- as.matrix(tdm)
  v <- sort(rowSums(m),decreasing=TRUE)
  d <- data.frame(word = names(v),freq=v)
  
  pal = brewer.pal(9, "RdPu")
  pal <- pal[-(1:4)]
  
  wordcloud(words = d$word, freq = d$freq, 
            min.freq = 1, max.words = Inf,
            random.order = FALSE, colors = pal,vfont=c("sans serif","plain"))
}