title: De-aggregate / reverse-summarise / expand a dataset in R
body: <p>My data looks like this:</p>
  
  <pre><code>data("Titanic")
  df &lt;- as.data.frame(Titanic)
  </code></pre>
  
  <p>How can I de-aggregate or reverse-summarise count/freq and expand the data set back to it's original non-count observation state?</p>
  
  <p>For instance, I want <code>3rd, Male, Child, No</code> repeated 35 times and <code>1st, Female, Adult, Yes</code> repeated 140 times, etc, etc, in the dataframe.</p>
  
  <p>Thanks in advance.</p>