fj-contrib

[jmduarte]

• Add fastjet-contrib as a submodule
• Compile fastjet-contrib as part of setup.pyas a submodule
• Reuse LundPlane code from fastjet-contrib
• Check if it runs/passes tests

This approach adds some overhead (compiling all of fastjet-contrib), but in principle allows us to add helper functions to use other contributions like SoftDrop, Nsubjettiness, EnergyCorrelationFunctions, etc.

[jmduarte]

The error occurs when importing fastjet so I'm not compiling/linking things appropriately. Maybe @chrispap95 or someone else has a clue on how to fix it?

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/opt/python/cp39-cp39/lib/python3.9/site-packages/fastjet/__init__.py", line 7, in <module>
    import fastjet._ext  # noqa: F401, E402
ImportError: /opt/python/cp39-cp39/lib/python3.9/site-packages/fastjet/_ext.cpython-39-x86_64-linux-gnu.so: undefined symbol: _ZTVN7fastjet7contrib13LundGeneratorE

[chrispap95]

@jmduarte it seems that each contrib is creating a .a lib and these libs are not linked against _ext. Perhaps, you could add these somehow inPybind11Extension(..., library_dirs=[], ... ). The only problem I see is that these plugins generate static libraries and pybind11 seems to look only for shared libs. @henryiii might know how to solve this.

[lgray]

We can probably wait to create a new release since the current implementation is correct as far as I can tell. Otherwise this looks fine.