On: A map of one million scientific papers from the ar...

[udev]

This map is beautiful!

But what does (x,y) position mean? If two papers are close on the map are they also close in some other aspect?

I mean, what gave this map this particular shape?

[Buetol → udev]

This has been most probably applied a force-directed layout: https://en.wikipedia.org/wiki/Force-directed_graph_drawing

Basically, it's like having a spring between each node (paper) and letting the equilibrium do the rest.

[carlob → Buetol]

Yes. From their facebook about page:

> In laying out the map, an N-body algorithm is run to determine positions based on references between the papers. There are two “forces” involved in the N-body calculation: each paper is repelled from all other papers using an anti-gravity inverse-distance force, and each paper is attracted to all of its references using a spring modelled by Hooke’s law.

However it must have taken them a while to converge for 10^6 particles.

[Buetol → carlob]

It's actually pretty fast now, could take max one day to get something like that with https://github.com/anvaka/ngraph.offline.layout

[t4ku → udev]

It's based on citations. If you go to 'about' on their site, there's more information about what x, y, size, color, brightness encode in the visualization.

[udev → t4ku]

If this is the case, I would love to see a similar map for IEEE papers. The citations are free to view on IEEE website.