title: How to min_max_scale test data by group, using the grouped min max of train data?
body: <p>For example, the dataset is like:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th>Group</th>
  <th>A</th>
  <th>B</th>
  <th>C</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td>1</td>
  <td>0.1</td>
  <td>0.2</td>
  <td>0.3</td>
  </tr>
  <tr>
  <td>1</td>
  <td>0.7</td>
  <td>0.34</td>
  <td>0.67</td>
  </tr>
  <tr>
  <td>2</td>
  <td>0.3</td>
  <td>0.1</td>
  <td>0.5</td>
  </tr>
  <tr>
  <td>2</td>
  <td>0.54</td>
  <td>0.6</td>
  <td>0.2</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>I want to use the min and max values of every column of the training dataset to scale the test data for each column separately, which also have a similar structure. THANK YOU!</p>