说明：  在前面1维，2维的基础上继续推出3维的FDTD程序，可以帮助解决复杂的3维电磁散射问题，适用范围更广。这个程序给出计算要求的参数即可运行。
(in front of one-dimensional, two-dimensional basis continue to offer three-dimensional FDTD procedures, which can help to solve the complex three-dimensional electromagnetic scattering problems, which have wider applicability. This procedure gives the parameters computing requirements can run.)