title: calculate accuracy and precision of confusion matrix
body: <p>Is there any tool / R package available to calculate accuracy and precision of a confusion matrix?</p>
  <p>The formula and data structure are <a href="http://www2.cs.uregina.ca/%7Edbd/cs831/notes/confusion_matrix/confusion_matrix.html" rel="nofollow noreferrer">here</a>.</p>