On Mon, Dec 07, 2015 at 01:44:47PM -0800, David Fifield wrote: > On Mon, Dec 07, 2015 at 02:51:23PM -0500, Philipp Winter wrote: > > I spent some time improving the existing relay uptime visualisation [0]. > > Inspired by a research paper [1], the new algorithm uses single-linkage > > clustering with Pearson's correlation coefficient as distance function. > > The idea is that relays are grouped next to each other if their uptime > > (basically a binary sequence) is highly correlated. Check out the > > following gallery. It contains monthly relay uptime images, dating back > > to 2007: > > <https://nymity.ch/sybilhunting/uptime-visualisation/> > > How about just taking the XOR of two sequences as the distance?
Here's Nov 2015, with XOR as distance: <https://nymity.ch/sybilhunting/uptime-visualisation/xor-distance.png> > It would be interesting to know if there are any near-perfect > anticorrelations; i.e., one relay starts when another stops. It looks like there's many of them. So far, I calculated the correlation as 1 - Pearson(s1,s2) because I'm only interested in positively correlated sequences. Here's an uptime image with Pearson(s1,s2) as distance function, so positive correlation is considered just as much as negative correlation. Have a look at the leftmost part: <https://nymity.ch/sybilhunting/uptime-visualisation/anticorrelation.png> Cheers, Philipp _______________________________________________ tor-dev mailing list tor-dev@lists.torproject.org https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-dev