Problem: K-Means clusterer only uses x-y coordinates

[nicolaspayette]

It was included in the nw extension because it's part of Jung and was easy to add.

I thought it could be modified to use network distance for the clustering, but I realized later that k-means is not an appropriate algorithm for that.

K-means clustering is still a useful thing, but probably should not be part of the nw extension if it doesn't work with networks. It would be desirable to replace it with an appropriate clusterer, though.

If we do remove it, maybe it could be moved to a separate extension, just in case someone was already using it.

[nicolaspayette]

If we keep it or move it somewhere else, @fstonedahl suggests:

How hard would it be to make it work using a custom reporter for each
agent, which returns a list of numbers?

i.e., something like:

nw:set-snapshot turtles links
let clusters nw:k-means-clusters [(list xcor ycor)] 10 500 0.01

or

let clusters nw:k-means-clusters [(list age wealth musical-ability)] 10 500 0.01

[nicolaspayette]

Removed in 259e00b.

[nicolaspayette]

Moved to separate extension: https://github.com/NetLogo/K-Means-Extension