>, nAGQ <span class="op">=</span> <span class="fl">15</span><span class="op">)</span></span></span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="co"># a diagonal covariance matrix for the random effects</span></span></span>
<span class="r-in"><span><span class="va">fm1_slp_diag</span> <span class="op">&lt;-</span> <span class="fu"><a href="https://rdrr.io/r/stats/update.html" class="external-link">update</a></span><span class="op">(</span><span class="va">fm1</span>, random 