<span class="op">=</span> <span class="st">"SFC SIMEX"</span><span class="op">)</span></span>
<span><span class="co">#&gt; Empty model created</span></span></code></pre></div>
<p>Define the variables for the model:</p>
<div class="sourceCode" id="cb3"><pre class="downlit sourceCode r">
<code class="sourceCode R"><span><span class="co"># Add variables</span></span>
<span><span class="va">model_simex</span> <span class="op">&lt;-</span> <span class="va">model_simex</span> <span class="op">|&gt;</span></span>
