An implementation of the PM-tree data structure for Nearest Neighbors search.
WARNING: this is very early stage, and not ready for usage.
Some preliminary performance numbers, on one million 25-dimensional GloVe vectors, with range queries with radius 2.0 and 4.0 and different parameterizations of the index.
group time (millis)
----- -------------
range query/B = 32 P = 4 r = 2.0 36.8±6.21msc
range query/B = 64 P = 4 r = 2.0 37.9±5.31msc
range query/B = 32 P = 8 r = 2.0 25.9±1.10msc
range query/B = 64 P = 8 r = 2.0 27.3±0.70msc
range query/B = 32 P = 4 r = 4.0 176.2±1.72msc
range query/B = 64 P = 4 r = 4.0 214.5±18.34msc
range query/B = 32 P = 8 r = 4.0 173.6±2.74msc
range query/B = 64 P = 8 r = 4.0 191.6±2.21msc