></span>
<span><span class="op">)</span></span></code></pre></div>
    </div>

    <div class="section level2">
    <h2 id="arguments">Arguments<a class="anchor" aria-label="anchor" href="#arguments"></a></h2>


<dl><dt id="arg-fixed">fixed<a class="anchor" aria-label="anchor" href="#arg-fixed"></a></dt>
<dd><p>two-sided linear formula object for the fixed-effects in the
linear mixed model. The response outcome is on the left of <code>~</code> and the
covariates are separated by <code>+</code> on the right 