KDTree Implementation in Java

I'm looking for a KDTree implementation in Java.
I've done a google search and the results seem pretty haphazard. There are actually lots of results, but they're mostly just little one-off implementations, and I'd rather find something with a little more "production value". Something like apache collections or the excellent C5 collection library for .NET. Something where I can see the public bug tracker and check to see when the last SVN commit happened. Also, in an ideal world, I'd find a nice well-designed API for spatial data structures, and the KDTree would be just one class in that library.

For this project, I'll only be working in either 2 or 3 dimensions, and I'm mostly just interested in a good nearest-neighbors implementation.

Solution 1:

In the book Algorithms in a Nutshell there is a kd tree implementation in java along with a few variations. All of the code is on oreilly.com and the book itself also walk you through the algorithm so you could build one yourself.

Solution 2:

for future seekers. Java-ml library has a kd-tree implementation that work fine. http://java-ml.sourceforge.net/

Solution 3:

I've had success with Professor Levy's implementation found here. I realize you're looking for a more production-certified implementation so this is probably not a good fit.

However note to any passers-by, I've been using it for a while now in my photomosaic project with no issues. No guarantee but better than nothing :)