Fabulous code for spherical Fourier-Bessel decomposition

The spherical Fourier-Bessel (SFB) decomposition is a natural choice for the radial/angular separation that allows extraction of cosmological information from large volume galaxy surveys, taking into account all wide-angle effects. In this paper we develop SFB power spectrum estimator measurement largest angular and radial modes with next generation surveys. code measures pseudo-SFB spectrum, takes mask, selection function, pixel window, shot noise. We show local average effect (or integral constraint) significant only in largest-scale mode, provide an analytical covariance matrix. By imposing boundary conditions at minimum maximum radius encompassing survey volume, does not suffer numerical instabilities have proven challenging analyses past. demonstrated on simplified but realistic Roman-like, SPHEREx-like, Euclid-like mask functions. For intuition validation, also explore Limber approximation. release associated public written julia.