f Poisson regression than a manually written
regression in terms of a Poisson likelihood and matrix multiplication.</p>
<div id="probability-mass-function-5" class="section level3">
<h3><span class="header-section-number">14.7.1</span> Probability Mass Function</h3>
<p>If <span class="math inline">\(x\in \mathbb{R}^{n\cdot m}, \alpha \in \mathbb{R}^n, \beta\in \mathbb{R}^m\)</span>, then for <span class="math inline">\(y \in \mathbb{N}^n\)</span>, <span class="math display">\[
\text{PoisonLogGLM}(y|x, \alph