title: How to calculate IDF?
body: <p>Thank you guys on this website you helped in TF/IDF. It helped me alot to make tf-idf function in java. I made tf but I have one question. As on wiki they wrote IDF can be calculated that how many documents have the term. But I am confused.</p>
  
  <p>For example, Here is the string "JosAH is great. JoshAH rocks" so the TF would be 2/5 and for IDF there are 2 documents and each documents contain JoshAH term. So
  Will we just see if that term occur in other documents or we will see how many times it occurs in other documents?</p>