On the computing algorithms of the hybrid FEM/MLFMA

Several computing algorithms of the hybrid FEM/MLFMA, the conventional algorithm (CA), the direct-iterative decomposition algorithm (DIDA), and a new one, the iterative-iterative decomposition algorithm (IIDA), are described in this Letter. The required computing resources of these three algorithms are compared analytically and numerically. Several important numerical features of these algorithms are pointed out and confirmed Criteria are given for the choice of computing algorithms.