All, I am a first time user of Mahout. I checked out the code and was able to get the build going. I was checking the Tasks list (I use Eclipse) and saw one in the LogLikelihoodTest.java to check the epsilons.
While checking the code in the LogLikelohood.java (org.apache.mahout.math.stats.Loglikelihood.java), I saw that the code for the Shannon entropy calculation seemed different from the one as it is defined on Wikipedia [http://en.wikipedia.org/wiki/Entropy_(information_theory)]. I wrote a small python script (attached- llr.py) to compare the one that is present in Mahout (org.apache.mahout.math.stats.Loglikelihood.java) and the one that is defined by Ted Dunning in http://tdunning.blogspot.com/2008/03/surprise-and-coincidence.html. Even though the entropy and LLR calculations are different, the final output of the LLR is the same with both the methods. I am trying to find out why both the methods are equivalent. Can you please let me know why this is the case or if there is a reference I can check I shall do that. If this is not the list for this question, I am sorry, I shall try the mahout-users list. Thank you Gangadhar
