A recursive aggregation method for the computation of electromagnetic scattering by randomly distributed particles

We develop a new algorithm to expedite the matrix‐vector multiplication in using the conjugate gradient method to solve the linear algebraic equation of scattering by a cluster of particles. We compare this method of solving the scattering problem with two other methods. One is our previously developed method, called recursive aggregate T‐matrix method. The second one is the direct use of the conjugate gradient method. Our new method is shown to have reduced computational complexity as well as memory requirement compared to the use of the conjugate gradient directly to solve the linear algebraic equation of scattering. © 1993 John Wiley & Sons, Inc.