Pure python implementation of factional cascading layered range tree

• only depends on python standard libraries when using (needs setuptools for installing, of course)
• O(n*log(n)**d) space complexity
• O(n*log(n)**d) constructing time complexity
• O(log(n)**(d-1)+k) querying time complexity

Only supports Python 3 now.

All comparable python objects are OK.

When limit to numpy 3d array with len(x)>1000, this query implementation is commonly faster than scipy.spatial.KDTree.(but is still slower than scipy.spatial.cKDTree due to Python intrinsic speed)

The construction time is much longer than kd-trees so this layered range tree is suitable for a large data set with an event larger number of query times.

checkout and install:

git clone https://github.com/epsilony/pyflrtree.git
pip install -e pyflrtree

query multi-dimensional data:

from flrtree import LRTree

...
tree=LRTree(data)

indes=tree.query(lower,upper)

run some blackbox tests:

import flrtree
flrtree.test()