title: wordcloud package: get “Error in strwidth(…) : invalid 'cex' value”
body: <p>I am using the tm and wordcloud packages in R 2.15.1. I am trying to make a word cloud Here is the code:</p>
  
  <pre><code>maruti_tweets = userTimeline("Maruti_suzuki", n=1000,cainfo="cacert.pem")
  hyundai_tweets = userTimeline("HyundaiIndia", n=1000,cainfo="cacert.pem")
  tata_tweets = userTimeline("TataMotor", n=1000,cainfo="cacert.pem")
  toyota_tweets = userTimeline("Toyota_India", n=1000,cainfo="cacert.pem")
  # get text
  maruti_txt = sapply(maruti_tweets, function(x) x$getText())
  hyundai_txt = sapply(hyundai_tweets, function(x) x$getText())
  tata_txt = sapply(tata_tweets, function(x) x$getText())
  toyota_txt = sapply(toyota_tweets, function(x) x$getText())
  clean.text = function(x)
  
  {
     # tolower
     x = tolower(x)
     # remove rt
     x = gsub("rt", "", x)
     # remove at
     x = gsub("@\\w+", "", x)
     # remove punctuation
     x = gsub("[[:punct:]]", "", x)
     # remove numbers
     x = gsub("[[:digit:]]", "", x)
     # remove links http
     x = gsub("http\\w+", "", x)
     # remove tabs
     x = gsub("[ |\t]{2,}", "", x)
     # remove blank spaces at the beginning
     x = gsub("^ ", "", x)
     # remove blank spaces at the end
     x = gsub(" $", "", x)
     return(x)
  }
  # clean texts
  maruti_clean = clean.text(maruti_txt)
  hyundai_clean = clean.text(hyundai_txt)
  tata_clean = clean.text(tata_txt)
  toyota_clean = clean.text(toyota_txt)
  maruti = paste(maruti_clean, collapse=" ")
  hyundai= paste(hyundai_clean, collapse=" ")
  tata= paste(tata_clean, collapse=" ")
  toyota= paste(toyota_clean, collapse=" ")
  # put ehyundaiything in a single vector
  all = c(maruti, hyundai, tata, toyota)
  # remove stop-words
  all = removeWords(all,
  c(stopwords("english"), "maruti", "tata", "hyundai", "toyota"))
  # create corpus
  corpus = Corpus(VectorSource(all))
  # create term-document matrix
  tdm = TermDocumentMatrix(corpus)
  # convert as matrix
  tdm = as.matrix(tdm)
  # add column names
  colnames(tdm) = c("MARUTI", "HYUNDAI", "TATA", "TOYOTA")
  # comparison cloud
  comparison.cloud(tdm, random.order=FALSE,colors = c("#00B2FF", "red",     #FF0099","#6600CC"),max.words=500)
  </code></pre>
  
  <p>but getting following error</p>
  
  <pre><code>Error in strwidth(words[i], cex = size[i], ...) : invalid 'cex' value
  please help
  </code></pre>