The VoidFinder algorithm by Hoyle & Vogeley (2002) is based upon the algorithm described by El-Ad & Piran (1997). It removes all isolated galaxies (described as having the third nearest-neighbor more than ~7 Mpc/h away) using only galaxies with absolute magnitudes Mr < -20. After applying a grid to the remaining galaxies, spheres are grown from all empty cells until it is bounded by four galaxies on the surface. A sphere must have a minimum radius of 10 Mpc/h to be considered part of a void. If two spheres overlap by more than 10% of their volume, they are considered part of the same void.
Please cite Hoyle & Vogeley (2002) and El-Ad & Piran (1997) when using this algorithm.
VoidFinder now includes some cythonized code for speed. To build this code, enter the
/python/voidfinder/ directory and run:
cython -a *.pyx
python setup.py build_ext --inplace
then from the /python/scripts/ directory edit the paths in whichever run script desired and run
as normal (example: python SDSS_Voidfinder.py).
The current version of VoidFinder is written to run with Python 3.