# Biff¶

Biff is a Python package for evaluating basis function expansions of mass densities and gravitational potentials.

Currently, the only implemented expansion is the Self-Consistent Field (SCF) method of Hernquist & Ostriker (1992; [HO92]) using Hernquist radial functions and spherical harmonics for angular functions. This implementation is based on the formalism described in the original paper but using the notation of Lowing et al. (2011; [L11]).

Note

Once it is more stable, Biff may be merged in to gala.potential .