Most of these metrics are based on counts so a combiner would definitely help.
On Jul 18, 2011, at 12:31, Sean Owen <[email protected]> wrote: > The combiner question is interesting. Many metrics happen to be built > up from some commutative function of smaller parts, like addition. I > think the answer is 'yes' in many cases -- but not in all cases. For > example I don't think you can construe log-likelihood this way. I'm > also not sure how Pearson would come out since you need the mean from > the start, though I wouldn't be surprised if there's a clever way to > compute it online.
