title: Create data from before row
body: <pre><code>example &lt;- data.frame(x = c(1000, ""  ,""  ,"" ))
  </code></pre>
  
  <p>What is the R´s function to get this?</p>
  
  <pre><code>example &lt;- data.frame(x = c(1000, 500, 250, 125))
  </code></pre>