</h2>
<p>Stan also supplies a single function for a generalized linear model with Poisson likelihood and log link function, i.e.Â a function for a Poisson regression. This provides a more efficient implementation of Poisson regression than a manually written regression in terms of a Poisson likelihood and matrix multiplication.</p>
<div id="probability-mass-function-15" class="section level3">
<h3><span class="header-section-number">13.7.1</span> Probability Mass Function</h3>
<p>If <span class="math inli