  We provide a detailed user guide for SMARTIES, a suite of Matlab codes for
the calculation of the optical properties of oblate and prolate spheroidal
particles, with comparable capabilities and ease-of-use as Mie theory for
spheres. SMARTIES is a Matlab implementation of an improved T-matrix algorithm
for the theoretical modelling of electromagnetic scattering by particles of
spheroidal shape. The theory behind the improvements in numerical accuracy and
convergence is briefly summarised, with reference to the original publications.
Instructions of use, and a detailed description of the code structure, its
range of applicability, as well as guidelines for further developments by
advanced users are discussed in separate sections of this user guide. The code
may be useful to researchers seeking a fast, accurate and reliable tool to
simulate the near-field and far-field optical properties of elongated
particles, but will also appeal to other developers of light-scattering
software seeking a reliable benchmark for non-spherical particles with a
challenging aspect ratio and/or refractive index contrast.
