title: Is tree.DecisionTreeRegressor a Model Tree or a Regression Tree?
body: <p>My understanding is that:</p>
  <ol>
  <li><p>In a <strong>Regression Tree</strong>: the target value of each leaf is calculated as the mean of the target values of the instances that reached that leaf during training.</p>
  </li>
  <li><p>In a <strong>Model Tree</strong>: the value of each leaf is a linear function using a subset of the features, determined by performing a linear regression of the instances that reached that leaf during training.</p>
  </li>
  </ol>
  <p>Is the <code>tree.DecisionTreeRegressor</code> in scikit-learn a <strong>Regression Tree</strong> or a <strong>Model Tree</strong>?</p>