title: order() function in R sorts integers "alphabetically"
body: <p>I start with a vector which I cbind() to a list of characters and then convert to a data frame as such:</p>
  
  <pre><code>numbers &lt;- c(110, 5, 43, 1008)
  mat &lt;- cbind(letters, numbers)
  letters &lt;- c("A", "B", "C", "D")
  df &lt;- data.frame(mat)
  </code></pre>
  
  <p>I applied the sorting:</p>
  
  <pre><code>df[order(df[,2]),]
  </code></pre>
  
  <p>and I get:</p>
  
  <pre><code>  letters numbers
  4       D    1008
  1       A     110
  3       C      43
  2       B       5
  </code></pre>
  
  <p>It's sorting the column as if it looks at the first number, then the second etc. and I CANNOT figure it out. The sort() function works on the column, but I can't seem to apply to all rows...</p>
  
  <p>Thanks!</p>