PML吸收边界三维FDTD算法MATLAB代码

%***********************************************************************
%     3-D FDTD code with UPML absorbing boundary conditions
%***********************************************************************
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%     Program author: Keely J. Willis Graduate Student
%                     UW Computational Electromagnetics Laboratory
%                           Director: Susan C. Hagness
%                     Department of Electrical and Computer Engineering
%                     University of Wisconsin-Madison
%                     1415 Engineering Drive
%                     Madison WI 53706-1691
%                     kjwillis@wisc.edu
%
%     Copyright 2005
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%     This MATLAB M-file implements the finite-difference time-domain
%     solution of Maxwell‘s curl equations over a three-dimensional
%     Cartesian space lattice comprised of uniform cubic grid cells.
%     
%     The dimensions of the computational domain are 8.2 cm
%     （x-direction） 3.4 cm （y-directio