using pynbody kdtree

[michele.ma...@gmail.com]

Hello,

I'd like to use pynbody kdtree functionality to find the list of neighbours of each particle. My ultimate goal is to do some SPH interpolation on the particles (computation of the curl).

I've seen there are the methods `nn` and `all_nn` in pynbody.sph.kdtree, which are used in kdmain.cpp.

But if I try to call them I get a segmentation fault.

```

import pynbody

s = pynbody.load('test_g2_snap.0')

pynbody.sph.build_tree(s)

print(s.kdtree.nn())   # <generator object KDTree.nn at 0x7fc2e95610d0>

s.kdtree.all_nn()      # Segmentation fault

```

Is there a way to obtain the list of each particle neighbours as computed by pynbody?

Thanks,

cheers,

Michele