Developer Notes

Welcome to the BanditPAM wiki!

This is a space for code contributors to keep track of notes and learnings that don't belong in Github issues.

Highly Requested Features that Mo won't have time to work on:

• An R implementation of BanditPAM
• An MATLAB implementation of BanditPAM

Less Requested Features that Mo won't have the time to work on:

• An integration with PySpark

Gotchas:

• setuptools will always, at least partly, use the compiler that Python was compiled with. This causes a problem, e.g., when trying to install clang-compiled BanditPAM on gcc-compiled Python and was resulting in errors. This CANNOT be fixed by modifying the CC environment variable. See https://github.com/pypa/setuptools/issues/1732
• You may occasionally get a bug like (Producer: 'LLVM13.0.0' Reader: 'LLVM 12.0.0'); somehow this was the case in base after uninstalling and reinstalling some brew packages. Weirdly, it was resolved by creating a new Python 3.8 conda environment, in which BanditPAM could be installed successfully, and then somehow (?!) fixed in base

Potential Cache Improvements:

• potentially transpose cache to avoid false sharing
• Move to multi-producer single-consumer queue for cache so that cache can be dynamically resized
• Give each thread a local copy of cache
• Helpful resource: Lecture 9 of series in OMP

Potential OpenMP Improvements:

• Good practice to have default(none) inside all omp parallel workspace constructs
• Prevent false sharing among threads for better speedups (This is dependent on local cache line size and datatype sizes)
• Consider using loop reductions via OpenMP

Github actions

• Right now, we compile with system python on the MacOS Github runners. It appears to work, though I'm not sure if the runners are using gcc or clang -- or if it matters, since the setup.py should detect it properly.

Potential frameworks to investigate:

• pbr
• Cython -- Cython will likely be MUCH faster. It's how the sklearn implementation of KMeans is written
• Numba

C++ frameworks to investigate:

• Eigen (pybind11 supports it out of the box, and we will likely no longer need carma or armadillo)
• Boost
• Folly