rmal}(y|\mu,\sigma) = \frac{1}{\sqrt{2
\pi} \ \sigma} \, \frac{1}{y} \ \exp \! \left(        - \, \frac{1}{2}
\, \left( \frac{\log y - \mu}{\sigma} \right)^2      \right) . \]</span></p>
</div>
<div id="sampling-statement" class="section level3">
<h3><span class="header-section-number">17.1.2</span> Sampling Statement</h3>
<p><code>y ~</code> <strong><code>lognormal</code></strong><code>(mu, sigma)</code></p>
<p>Increment target log probability density with <code>lognormal_lpdf(y | mu, sigma)</code>
droppin