op">[</span>, <span class="st">"d13C_Pl"</span><span class="op">]</span>,</span>
<span>  y <span class="op">=</span> <span class="va">geese_data_day1</span><span class="op">$</span><span class="va">mixtures</span><span class="op">[</span>, <span class="st">"d15N_Pl"</span><span class="op">]</span>,</span>
<span>  Source <span class="op">=</span> <span class="st">"Mixtures"</span></span>
<span><span class="op">)</span></span>
<span><span class="co"># Find the convex hull</span></span>
<span><span class="va">