Mesh Neighbor preconditioned IE-FFT solution

In this paper, the IE-FFT has been successfully implemented with the curvilinear basis function to solve scattering problems. The IE-FFT is used to speed up the matrix-vector multiplication. The CPU time per iteration is O(N^1.5log(N)) and the memory requirement is O(N^1.2). The MN preconditioner has been used to improve the convergence of the CG solver and the good performance has been shown. The speed up can achieve 6 times. The numerical results show that the IE-FFT has good accuracy and efficiency.