Stephen Wolfram actually did some analysis on this: http://blog.stephenwolfram.com/2013/04/data-science-of-the-facebook-world/ -- he has a nice plot of the distribution of friends (the median is 342).
-Dan On Sun, Sep 15, 2013 at 8:34 AM, Roger Hui <[email protected]> wrote: > Yes, I'd noticed the discrepancy between Richard's description (0-150) and > the Wikipedia page on Dunbar's number. Moreover, I doubt that the > distribution is uniform in the range (whether 0-150 or 0- >230). > > > On Sun, Sep 15, 2013 at 6:29 AM, Raul Miller <[email protected]> wrote: > >> On Sat, Sep 14, 2013 at 1:56 PM, Roger Hui <[email protected]> >> wrote: >> > I failed to do an example with 1e7 members. The expected number of >> friends >> > is 75 per the Dunbar requirement. For n members, the size of s is >> > (75*n),2. On J64, integers are 8 bytes each, so the total number of >> bytes >> > is 8**/(75*n),2 and for n=1e7 equates to 12 GB. >> >> Note also that the dunbar requirement in this thread is different from >> the dunbar number expressed at the wikipedia link (150 there was the >> average and expected averages were something in the range of 100-230 >> (and I'm not going to verify those numbers because (a) my mouse is >> acting up, and (b) the reasoning behind them was just too silly for me >> to make sense of)). >> >> That said, note that we have similarly structured information >> available in social networks (facebook graph, for example, but there >> are others). So hypothetically speaking, we could play with that data >> and see how similar those averages were to the dunbar averages. But, >> to do this, we'd undoubtably need greater than 12GB to represent the >> data. (I wonder if we have enough interest to put together enough of >> a community to implement J for infrastructures such as hadoop?) >> >> But note also that these toy problems - real problems at that scale >> are probably biological (or pornographic?) in character. (Genome >> project, was a recent example I noticed.) >> >> Thanks, >> >> -- >> Raul >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm >> > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
