Thank you for the explanation. I can understand the calculations now, but I still don't get the meaning. I think I'll try to sleep a night over it and try again tomorrow.

Best regards,
Thomas

Am 09.05.2011 03:42, schrieb Ted Dunning:
In this notation, k is assumed to be a matrix.  k_11 is the element in the
first row and first column.

I used k to sound like count.

The notation that you quote is R syntax.  rowSums is a function that
computes the row-wise sums of the argument k.  H is a function defined
elsewhere.

On Sun, May 8, 2011 at 6:33 PM, Thomas Söhngen<[email protected]>  wrote:

Thank you for the blog post and showing me the G-test formula.

After going through your blog post, I still have some open questions: You
introduce k_11 to k_22, but I don't understand what "k" itself actually
stands for in your formular and how the sums are defined: LLR = 2 sum(k)
(H(k) - H(rowSums(k)) - H(colSums(k)))

Am 09.05.2011 02:46, schrieb Ted Dunning:

  My guess is that the OP was asking about the generalized log-likelihood
ratio test used in the Mahout recommendation framework.

That is a bit different from what you describe in that it is the log of
the
ratio of two maximum likelihoods.

See http://en.wikipedia.org/wiki/G-test for a definition of the test used
in
Mahout.

On Sun, May 8, 2011 at 5:43 PM, Jeremy Lewi<[email protected]>   wrote:

  Thomas,
Are you asking a general question about log-likelihood or a specific
implementation usage in Mahout?

In general the likelihood is just a number, between 0 and 1 which
measures the probability of observing some data under some distribution.



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