e     pgm     -&gt;puncle    </span></span>
<span><span class="co">## + ... omitted several edges</span></span></code></pre>
<p>The object <code>graph</code> is a directed graph constructed from
the trio information in <code>family</code> and is build using the
<strong><em>igraph</em></strong> package. The direction in the graph is
from parent to offspring.</p>
</div>
<div class="section level3">
<h3 id="from-graph-to-subgraph-and-kinship-matrix">From graph to subgraph and kinship matrix<a class="anchor" ar