es is defined in the <em>lv</em> and the other is observed in the dataset. In addition, we specify a multi-group structural equation model using the <em>group</em> option.</p>
<div class="sourceCode" id="cb4"><pre class="downlit sourceCode r">
<code class="sourceCode R"><span class="va">m3</span> <span class="op">&lt;-</span> <span class="fu"><a href="../reference/countreg.html">countreg</a></span><span class="op">(</span><span class="va">dv</span> <span class="op">~</span> <span class="va">eta1</span> <sp