an><span class="op">(</span></span>
<span>    eta <span class="op">=</span> <span class="va">matrix</span></span>
<span>  <span class="op">)</span></span>
<span></span>
<span><span class="co"># Compare to Figure 8 of Heun, Owen, and Brockway (2018)</span></span>
<span><span class="va">etas_forgraphing</span> <span class="op"><a href="../reference/pipe.html">%&gt;%</a></span> <span class="fu"><a href="https://dplyr.tidyverse.org/reference/filter.html" class="external-link">filter</a></span><span class="op">(