iterative ref: compute_bayesean_weights

[geoffwoollard]

See

1. Nelson, P. C. (2019). Chapter 12 : Single Particle Reconstruction in Cryo-electron Microscopy.
   In Physical Models of Living Systems (pp. 305–325).
   https://repository.upenn.edu/cgi/viewcontent.cgi?article=1665&context=physics_papers

2. https://github.com/geoffwoollard/learn_cryoem_math/blob/master/nb/fourier_slice_2D_3D_with_trilinear.ipynb