# Issue

This Content is from Stack Overflow. Question asked by Vovin

I use `BallTree` structure from `scikitlearn` in order to find nearest points inside a radius. I have a geometry array consisting of 1203 points. It works well. For example, let’s find nearest points inside 100 km around an isolate from Fujisawa:

``````ball_tree = BallTree(
geometry_array,
metric="haversine",
)

isolate_index = foreign_AVP1.index.get_loc("LC035020.1")
).item()

foreign_AVP1.iloc[near_indices].locale
``````

taxon locale
LC037396.1 Japan Yokohama
LC035020.1 Japan Fujisawa
LC037395.1 Japan Yokohama
LC014787.1 Japan Tokyo
AB279734.1 Japan Tokyo

I was curious to look at the tree structure & used `get_tree_stats` method to know the leaves number. Unawares, I got zeros tuple: `(0, 0, 0)`. This is strange as there are a default leaf size 40 & the number of samples 1203 that should result in about 16-30 leaves. When I used `get_arrays` method to get the raw data I saw a normal picture (this is just a part), there are 16 leaves:

``````array([(   0, 1203, 0, 3.0947303 ), (   0,  601, 0, 2.41933654),
( 601, 1203, 0, 0.58490656), (   0,  300, 0, 1.85505229),
( 300,  601, 0, 0.89693236), ( 601,  902, 0, 0.49983081),
( 902, 1203, 0, 0.40970688), (   0,  150, 0, 1.48087714),
( 150,  300, 0, 0.32291627), ( 300,  450, 0, 0.20494666),
( 450,  601, 0, 0.81787611), ( 601,  751, 0, 0.55418562),
( 751,  902, 0, 0.33448889), ( 902, 1052, 0, 0.01141954),
(1052, 1203, 0, 0.39229974), (   0,   75, 1, 1.00467692),
(  75,  150, 1, 1.07852748), ( 150,  225, 1, 0.25955598),
( 225,  300, 1, 0.24115038), ( 300,  375, 1, 0.12721095),
( 375,  450, 1, 0.1702189 ), ( 450,  525, 1, 0.78454107),
( 525,  601, 1, 0.09367431), ( 601,  676, 1, 0.0368483 ),
( 676,  751, 1, 0.4762352 ), ( 751,  826, 1, 0.2375712 ),
( 826,  902, 1, 0.17776855), ( 902,  977, 1, 0.01107241),
( 977, 1052, 1, 0.0118055 ), (1052, 1127, 1, 0.32023704),
(1127, 1203, 1, 0.09146244)],
dtype=[('idx_start', '<i8'), ('idx_end', '<i8'), ('is_leaf', '<i8'), ('radius', '<f8')]),
``````

Why does the method `get_tree_stats` have the unexpected behavior?

# Solution

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