The .zip file at the end of the page contains the code for the chain-of-spheres approach developed in:
H. O. Caldag, S. Yesilyurt, “Acoustic Radiation Forces on Magnetically Actuated Helical Swimmers,” Physics of Fluids , 32, 092012, 2020. https://doi.org/10.1063/5.0020930
The code contains modified versions of the following piece of code for Bessel function evaluations:
Daniel Vangheluwe (2021). spherical Besselfunctions (https://www.mathworks.com/matlabcentral/fileexchange/8488-spherical-besselfunctions), MATLAB Central File Exchange.
Chain-of-Spheres.zip (Right-click to save)
Note that the code is provided as-is. There may remain some bugs or errors.