[tor-dev] Better relay uptime visualisation
phw at nymity.ch
Tue Dec 8 16:26:50 UTC 2015
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 .
> > Inspired by a research paper , 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:
> 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
More information about the tor-dev