from gala.potential import scf

mass = np.ones(n_samples) / n_samples
S,T = scf.compute_coeffs_discrete(xyz, mass=mass, nmax=20, lmax=0, r_s=1.)

plt.figure(figsize=(6,4))
plt.semilogy(np.abs(S[:,0,0]), marker=None, lw=2)
plt.xlabel("$n$")
plt.ylabel("$S_{n00}$")
plt.tight_layout()