title: duplicate rows in a data frame in R
body: <p>I am trying to duplicate rows in my data frame using the code below.
  However, I'm finding it to be slow.</p>
  
  <pre><code>duprow = df[1,]
  for(i in 1:2000)
  {
      print(i)
      df = rbind(df,duprow)
  }
  </code></pre>
  
  <p>Is there a faster way?</p>