title: Add name to boxplot in R
body: <p>This question is related to: <a href="https://stackoverflow.com/questions/25589211/r-how-to-label-the-x-axis-of-a-boxplot">R: how to label the x-axis of a boxplot</a></p>
  
  <p>When more than one column is plotted, names appear. But when only one column is plotted, name does not appear, even when names=.. argument is used: </p>
  
  <pre><code>ddf = structure(list(apple = c(1, 2, 3, 4, 5), banana = c(5, 4, 3, 
   2, 1), watermelon = c(4, 5, 6, 7, 8)), .Names = c("apple", "banana", 
   "watermelon"), row.names = c(NA, -5L), class = "data.frame")
  
   ddf
    apple banana watermelon
  1     1      5          4
  2     2      4          5
  3     3      3          6
  4     4      2          7
  5     5      1          8
  
  
  boxplot(ddf[,1:2])
  boxplot(ddf[,1])
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/SudON.png" alt="enter image description here"></p>
  
  <p><img src="https://i.stack.imgur.com/wZsmh.png" alt="enter image description here"></p>
  
  <p>Following also do not work:</p>
  
  <pre><code>boxplot(ddf[,1], names='apple')
  boxplot(ddf[,1], names=c('apple'))
  </code></pre>
  
  <p>How can I add name to the boxplot when only one column is used? Thanks for your help.</p>