title: R Clustering 'purity' metric
body: <p>I am using fpc package in R to perform cluster validation. </p>
  
  <p>I could use the function cluster.stats() to compare my clustering with an external partitioning and compute several metrics like Rand Index, entropy e.t.c.</p>
  
  <p>However, I am looking for a metric called 'purity' or 'cluster accuracy' which is defined in <a href="http://nlp.stanford.edu/IR-book/html/htmledition/evaluation-of-clustering-1.html" rel="noreferrer">http://nlp.stanford.edu/IR-book/html/htmledition/evaluation-of-clustering-1.html</a></p>
  
  <p>I am wondering if there is an implementation of this measure in R.</p>
  
  <p>thanks,
  Chet</p>