title: How to know about group information in cluster analysis (hierarchical)?
body: <p>I have problem about <strong>group</strong> in cluster analysis(hierarchical cluster). As example, this is the dendrogram of complete  linkage of <strong>Iris data set</strong>.</p>
  
  <p><img src="https://i.stack.imgur.com/tEZqS.png" alt="enter image description here"></p>
  
  <p>After I use </p>
  
  <pre><code>&gt; table(cutree(hc, 3), iris$Species)
  </code></pre>
  
  <p>This is the <strong>output</strong>:</p>
  
  <pre><code>  setosa versicolor virginica
  1     50          0         0
  2      0         23        49
  3      0         27         1
  </code></pre>
  
  <p>I have read in one statistical website that, object 1 in the data always belongs to group/cluster 1. From the output above, we know that <strong><em>setosa</em></strong> is in <strong>group 1</strong>. Then, how I am going to know about the other two species. How do they fall into either group 2 or 3. How did it happen. Perhaps there is a calculation I need to know?</p>