I've just made a map of tags for Physics.SE.

In short: tag size is related to tag popularity and edges are related to tag co-occurrences in questions.

For me it looks as a "snapshot" of topics and scope of this SE site. So if you want to you it in any way to promote Physics.SE - feel free!

Also, if you have comments how to improve its usefulness or niceness to our community, I would appreciate them (but bear in mind that I have no color esthetics).

Tag Map for Physics.SE


  • 5
    $\begingroup$ Nice :-) I might use it in a (personal) blog post later this month to promote your work and the site. $\endgroup$
    – David Z
    Nov 1, 2012 at 17:29
  • $\begingroup$ @DavidZaslavsky Nice to hear that! :) So just let me know (e.g. "+" in G+) when it happens. $\endgroup$ Nov 1, 2012 at 17:59
  • 2
    $\begingroup$ This is a cool representation of our community and it would make a good motive for a T-shirt :-) Can it be made dynamic such that it automatically adaptes the size and the links among the tags to include the newly incoming questions? $\endgroup$
    – Dilaton
    Nov 1, 2012 at 20:07
  • 3
    $\begingroup$ @Dilaton Dynamic version (most likely with d3js.org + SE API) is in my plans. However - depending on my energy & time, it may be sooner or later. But remember that dynamic, interactive plots may have some compatibility issues with T-Shirts ;). $\endgroup$ Nov 1, 2012 at 20:17
  • 4
    $\begingroup$ I like it a lot. Now what I want to add is some way to overlay a particular user's footprint (assuming the data can be obtained) - are they more of a particle physicist or a cosmologist? Maybe I'll play with the code. Odds of success: $\sim\varepsilon$. $\endgroup$
    – user10851
    Nov 2, 2012 at 8:24
  • 2
    $\begingroup$ Ha ha @ChrisWhite :-D, I thought about a similar idea about having the possibility to let each user draw such a diagram for the tags he uses (with the size given by # each tag is used or the points obtained from it). I personally should probably better refrain from using it, if such a feature existed, because it would make me look like a really really really bad geek :-P $\endgroup$
    – Dilaton
    Nov 2, 2012 at 10:44
  • 3
    $\begingroup$ Entropy being exactly in the middle, that doesn't make sense ;) $\endgroup$
    – Bernhard
    Nov 2, 2012 at 11:47
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    $\begingroup$ @Chris not too hard to do that, in fact. If you look at the instructions on github, you first have to download a CSV of a certain data.SE query. It's not too hard to fork the query and add a WHERE P.OwnerUserId=##UserId## clause in a few places. I've tried it out, see data.stackexchange.com/physics/query/84235/…. Just use the CSV from that and follo the rest of the procedure. $\endgroup$ Nov 4, 2012 at 5:32
  • 1
    $\begingroup$ @Manishearth Just a small warning - here statistics matters. That is, I plotted 64 tags for the whole physics.SE, as for 128 tags there was too much noise (e.g. edges for only 1 co-occurrence). Instead, I was thinking about making a heat-map over the full graph. Anyway - did you try plotting it for any particular user? $\endgroup$ Nov 4, 2012 at 10:27
  • 1
    $\begingroup$ @PiotrMigdal: Not yet, I've not got access to my Ubuntu laptop atm. I'll try it later, and I'll edit the query to take care of the 64-tag restriction. $\endgroup$ Nov 4, 2012 at 10:35
  • $\begingroup$ @PiotrMigdal: How did you get them grouped like that? Is there some procedure? TH one on the GH README isn't doing the trick.. $\endgroup$ Dec 5, 2012 at 19:10
  • $\begingroup$ @Manishearth You mean - colored or positioned? (And what's "TH"?) $\endgroup$ Dec 5, 2012 at 19:16
  • $\begingroup$ @PiotrMigdal: Colored AND positioned. The Phys.SE one is pretty, I can't manage to make it that pretty for chem and Linguistics :\ And the grouping is meaningful (it looks meaningful, at any rate), so that helps. "TH" was me mistyping "The" :P (and GH=GitHub) $\endgroup$ Dec 5, 2012 at 19:21
  • $\begingroup$ @Manishearth Strange, it is there Layout -> ARF -> Run for an example Layout (you can try others), Statistics -> Modularity -> Run then Partition -> Nodes -> Refresh -> Modularity Class -> Apply are for the coloring. Which part isn't working for you (I know that the Gephi UI is not the intuitive or even logical). $\endgroup$ Dec 5, 2012 at 19:25
  • 1
    $\begingroup$ @Dilaton Anyway, to get graph I need to use all data, data from 3 months would not suffice for correlations (but very likely is perfectly enough for just graph counts). BTW: If you just want to see tag popularity over time, it's enough to use data.stackexchange.com. E.g. data.stackexchange.com/stackoverflow/query/83404/… plus a filter on post dates. $\endgroup$ Feb 8, 2013 at 12:13

1 Answer 1


I find it weird that QM is all alone in that corner there. Are there really so many QM-QI links to dwarf, say the QM-photons, light, QFT, etc., edges?

  • 1
    $\begingroup$ Is short - links are only for very specific connections. If a given topic os connected with many things, but roughly in the same way, then there are not many links from it. It's an effect of taking $P(\text{tag1}\cap\text{tag2})/[P(\text{tag1})P(\text{tag2})]$ as measure of being connected. See also discussions here on "homework" and "linear algebra". Otherwise it would be hard to plot it (tried, failed) as some topics would be connected to almost everything (e.g. quantum mechanics) while many other - to nothing. $\endgroup$ Nov 5, 2012 at 20:04

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