}{1 - h_{ii}} \quad\quad R_i = \frac{q_{ii}}{1 - h_{ii}} \;.$$
 \(R_i\) is the studentized residual, and \(D_i \propto L_i \times R_i\).</p>
<p>In the general, multivariate case there are analogous matrix expressions for \(\mathbf{L}\) and \(\mathbf{R}\).
 When <code>m &gt; 1</code>, the quantities \(\mathbf{H}_I\), \(\mathbf{Q}_I\), \(\mathbf{L}_I\), and
 \(\mathbf{R}_I\) are \(m \times m\) matrices.  Where scalar quantities are needed, the package functions apply
 a function, <code>FUN</code>, either <cod