al}(0, \Sigma).
\]</span>
It then alternates half-step updates of the momentum and full-step
updates of the position.</p>
<p><span class="math display">\[
\begin{array}{rcl}
\rho &amp; \leftarrow
     &amp; \rho \, - \, \frac{\epsilon}{2} \frac{\partial V}{\partial \theta}
\\[6pt]
\theta &amp; \leftarrow
       &amp; \theta \, + \, \epsilon \, \Sigma \, \rho
\\[6pt]
\rho &amp; \leftarrow
     &amp; \rho \, - \, \frac{\epsilon}{2} \frac{\partial V}{\partial \theta}.
\end{array}
\]</span></p>
<p>By applying <