USING FAST FOURIER TRANSFORM IN THE 3-D MULTILEVEL FAST MULTIPOLE ALGORITHM

Abstract. In this paper a method is presented how to perform interpolation and anterpolation in both spherical coordinates µ and Á by trigonometric polynomials and the fast Fourier transform (FFT) in the 3-D multilevel fast multipole algorithm (MLFMA). The proposed method is exact in interpolation and anterpolation, and has the high numerical e±ciency of FFT. A numerical comparison suggests that the proposed method is equally or more e±cient, depending on the desired accuracy, than the method of using spherical harmonics and polynomial interpolation in interpolation and anterpolation. 1