t</em><sub><em>k</em></sub></sub></span>.</p>
<p>The <strong>ctsmTMB</strong> package is essentially wrapper around the <strong>TMB/RTMB</strong> packages <a href="https://github.com/kaskr/adcomp" class="external-link">(Template Model Builder)</a> that provide automatic differentiation of the likelihood function, and access to other computational tools such as the Laplace approximation. The likelihood function is constructed based on the (symbolic) user-provided state space equations, which may be specified