title: Calculate Precision and Recall
body: <p>I am really confused about how to calculate Precision and Recall in Supervised machine learning algorithm using NB classifier</p>
  
  <p>Say for example<br>
  <strong>1)</strong> I have two classes A,B<br>
  <strong>2)</strong> I have 10000 Documents out of which 2000 goes to training Sample set (class A=1000,class B=1000)<br>
  <strong>3)</strong> Now on basis of above training sample set classify rest 8000 documents using NB classifier<br>
  <strong>4)</strong> Now after classifying 5000 documents goes to class A and 3000 documents goes to class B<br>
  <strong>5)</strong> Now how to calculate Precision and Recall? </p>
  
  <p>Please help me..</p>
  
  <p>Thanks</p>