">mix</span><span class="op">(</span><span class="va">Reaction</span> <span class="op">~</span> <span class="va">Days</span> <span class="op">+</span> <span class="op">(</span><span class="fl">1</span><span class="op">|</span><span class="va">Subject</span><span class="op">)</span>, data<span class="op">=</span><span class="va">ss1</span>, weights<span class="op">=</span><span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">"W1"<