title: R. How to calculate level based on number in one dataframe?
body: <p>This is probably a super easy and basic question but I can't find answer. I have a data frame with some nums. And I need to add another column to that database with strings that would represent this data. What I mean, for example:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>A header</th>
  <th>Another header</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>10</td>
  <td>Bad</td>
  </tr>
  <tr>
  <td>20</td>
  <td>Good</td>
  </tr>
  <tr>
  <td>15</td>
  <td>Bad</td>
  </tr>
  <tr>
  <td>35</td>
  <td>Good</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>&quot;Bad&quot; and &quot;Good&quot; is intervals, for example, &quot;Bad&quot; is 0-20 and &quot;Good&quot; is 20+.
  How do I do that with R? I think I need to use apply func.</p>