Regarding Open Interest

General
1

  1. How can i track the OI changes during market hours for different nifty calls & puts? Whether any indicator/trend (Software) to plot the OI changes like volume trend? While trading in Nifty options, tracking Nifty futures open interest can give any useful information?

  2. How to calculate %change in OI?

2

Question 1 = http://www.niftytrader.in/live-nifty-open-interest/

Question 2 = % Change in open interest = (Current Open Interest - Previous day closing open interest)/Previous day closing open interest * 100