work trees: A method for recursively partitioning covariance structures. Psychometrika, 85(4), 926-945. https://doi.org/10.1007/s11336-020-09731-4</p>

    <h2 class="hasAnchor" id="examples"><a class="anchor" href="#examples"></a>Examples</h2>
    <pre class="examples"><div class='input'>
<span class='fu'><a href='https://rdrr.io/r/base/Random.html'>set.seed</a></span><span class='op'>(</span><span class='fl'>1</span><span class='op'>)</span>
<span class='va'>d</span> <span class='op'>&lt;-</span> <span cl