title: Changing row in data frame to ffactor
body: <p>I have a data frame where the last column is a numerical variable that shows the location of the row (so basically it starts at 1 and ends at the number of the last row).</p>
  <p>I want to change that into a factor so that the first 10 are level = &quot;First 10&quot;, second 10 are level = &quot;Second 10&quot;
  I am unable to think of where to start except by as.factor</p>