CoverTree

This is a Python implementation of cover trees, a data structure for finding nearest neighbors in a general metric space (e.g., a 3D box with periodic boundary conditions).

Cover trees are described in two papers hosted here:

http://hunch.net/~jl/projects/cover_tree/cover_tree.html

The implementation here owes a great deal to PyCoverTree, by Thomas Kollar, Nil Geisweiller, Emanuele Olivetti, which can be found here:

http://github.com/emanuele/PyCoverTree

The API follows that of Anne M. Archibald's KD-tree implementation for scipy (scipy.spatial.kdtree). Other than specifying a distance function in the constructor, this module can be used as a drop-in replacement for kdtree.