On Mon, Aug 10, 2015 at 1:11 PM, nusenu <nus...@openmailbox.org> wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA512 > > Hi, > > https://gitweb.torproject.org/torspec.git/tree/dir-spec.txt#n2028 > >> If 3 or more authorities provide a Measured= keyword for a router, >> the authorities produce a consensus containing a "w" Bandwidth= >> keyword equal to the median of the Measured= votes. > > a random sample from recent votes: > > grep 37.59.38.117 -A 3 *|grep Measured > w Bandwidth=6869 Measured=7570 > w Bandwidth=6869 Measured=15500 > w Bandwidth=6869 Measured=18100 > w Bandwidth=6869 Measured=30500 > > Tor says the median value is > 15500 > > 2015-08-10-16-00-00-consensus: > w Bandwidth=15500 > > but the median of these 4 values is actually: > (18100+15500)/2 = 16800 > no? > > Has tor a different definition of 'median' and simply takes always the > second ordered measurement vote out of 4 votes or is there a bug in > the spec or implementation?
There's one misplaced throwaway sentence in dir-spec.txt: " All ties in computing medians are broken in favor of the smaller or earlier item. " We should bring this, and probably other things, into a "definitions" section earlier in dir-spec.txt. Patches welcome. ;) -- Nick _______________________________________________ tor-dev mailing list tor-dev@lists.torproject.org https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-dev