Such as use preconditioned conjugate gradient (PCG) algorithm to reduce the iterative steps, use modified multipole numbers method to reduce the computation of each step.

• (1)在给定精度前提下减少迭代步数,采用适合于快速多极子方法的矩阵预条件技术,改善矩阵的条件数,加快迭代收敛。