On 4 April 2011 18:17, jacob <[email protected]> wrote: > I wrote a post on a similar problem with pig. Finding similarity between > comic book characters ;) > > http://thedatachef.blogspot.com/2011/02/brute-force-graph-crunching-with-pig.html
:) You're calling out to Ruby for Jaccard; might be worth trying to wire up Mahout instead, since Pig's happy (happier?) invoking Java methods... http://people.apache.org/~isabel/mahout_site/mahout-core/apidocs/org/apache/mahout/cf/taste/impl/similarity/TanimotoCoefficientSimilarity.html Anyone tried something like that? Dan > --jacob > @thedatachef > > On Sun, 2011-04-03 at 20:49 +0000, Diallo Mamadou Bobo wrote: >> Hi There. >> We need as part of our start-up product to compute "similar user feature". >> And we've decided to go with pig for it. >> I've been learning pig for a few days now and understand how it work. >> So to start here is how the log file look like. >> >> user url time >> user1 http://someurl.com 1235416 >> user1 http://anotherlik.com 1255330 >> user2 http://someurl.com 1705012 >> user3 http://something.com 1705042 >> user3 http://someurl.com 1705042 >> >> As the number of users and url can be huge, we can't use a bruteforce >> approach here, so first we need to find the user's that have access at least >> to on common url. >> >> The algorithm could be splited as bellow: >> >> 1. Find all users that has accessed to some common urls. >> 2. generate pair-wise combination of all users for each resource accessed. >> 3. for each pair and and url, compute the similarity of those users: the >> similarity depend of the timeinterval between the access (so we need to keep >> track of the time). >> 4. sum up for each pair-url the similarity. >> >> here is what i've written so far: >> >> A = LOAD 'logs.txt' USING PigStorage('\t') AS (uid:bytearray, url:bytearray, >> time:long); >> grouped_pos = GROUP A BY ($1); >> >> I know it is not much yet, but now i don't know how to generate the pair or >> move further. >> So any help would be appreciated. >> >> Thanks. > > >
