gt;</span> Formula: Reaction ~ Days + (Days | Subject)</span>
<span class="r-out co"><span class="r-pr">#&gt;</span>    Data: sleepstudy</span>
<span class="r-out co"><span class="r-pr">#&gt;</span>  Subset: Days &gt;= 2</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> REML criterion at convergence: 1404.094</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> Random effects:</span>
<span class="r-out co"><span class="r-pr">#&gt;</span>  Groups   Name        Std.Dev. Corr </span>
<span