an><span class="co"># An effects plot for the mean subject (i.e., with random effects equal to 0)</span></span></span>
<span class="r-in"><span><span class="va">nDF</span> <span class="op">&lt;-</span> <span class="fu"><a href="https://rdrr.io/r/base/with.html" class="external-link">with</a></span><span class="op">(</span><span class="va">DF</span>, <span class="fu"><a href="https://rdrr.io/r/base/expand.grid.html" class="external-link">expand.grid</a></span><span class="op">(</span>year <span class="op">=<