lass="op">&lt;-</span> <span class="fu"><a href="https://rdrr.io/r/base/data.frame.html" class="external-link">data.frame</a></span><span class="op">(</span></span></span>
<span class="r-in"><span>  id <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">"pid"</span>, <span class="st">"mom"</span>, <span class="st">"dad"</span>, <span class="st">"pgf"</span><span class="op">)</span>,</span></span>
<span