sing a fake example)</span></span></span>
<span class="r-in"><span><span class="co">## fit first response</span></span></span>
<span class="r-in"><span><span class="va">fit1</span> <span class="op">&lt;-</span> <span class="fu"><a href="lmer.html">lmer</a></span><span class="op">(</span><span class="va">y</span> <span class="op">~</span> <span class="va">x</span><span class="op">+</span><span class="op">(</span><span class="fl">1</span><span class="op">|</span><span class="va">f</span><span class="op">)</sp