title: Writing array to CSV, unexpected behaviour for col.names = F
body: <p>I am trying to write an array to a CSV without the row and column names. Setting the column names to false doesnt seem to work. I get "x" for the column name and a warning.</p>
  
  <p>Any ideas how to remove this "x"?</p>
  
  <pre><code>write.csv(1:5, row.names = F, col.names = F)
  
  # "x"
  # 1
  # 2
  # 3
  # 4
  # 5
  # Warning message:
  #   In write.csv(1:5, row.names = F, col.names = F) :
  #   attempt to set 'col.names' ignored
  </code></pre>