[已解决]Sullivan 写的两个程序FDTD1D_1.5和FDTD_2.1模拟相同的情景为什么输出的结果不同呀

哪位高手指点下：Sullivan 写的两个程序FDTD1D_1.5和FDTD_2.1模拟相同的情景（即正弦波通过损耗介质）为什么输出的结 .. <&2,G5XA  
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两个都是1D的？ Rn(F#tI  
代码贴出来？

FDTD1D_1.5 K<  
C\2>7  
x*"pDI0k)  
delta_x = .01;%Set the cell size to 1cm OjlB0  
delta_t = delta_x/(2*3e8);%Calculate the time step NT9- j#V  
max_time = 500;% time is be limited $17 v,  
max_space = 200; xVz -_z  
E = zeros(max_space,1); -kri3?Y,  
H = E; MN M>  
dielectric_begin = 100; +JAfHQm-  
dielectric_end = max_space; JS7}K)A2B6  
dielectic_space_a = ones(max_space,1); 0/00W6r0  
dielectic_space_b = ones(max_space,1); <\9Ijuq}k  
eta = 0.5; V?V)&y] 4  
dielectric_constant = 4; fRa-bqQ  
etaeps = eta/dielectric_constant; 9c5G6n0  
%Lossy Medium variables - for non-Lossy medium set sigma = 0; *ez~~ Y  
sigma = 0.04; (=tF2YBV  
epszero = 8.85419e-12; aU]O$Pg{  
loss_term = (delta_t*sigma) / (2*epszero*dielectric_constant); Z=Y_;dS9  
%ABS needed for LHS of problem space do not work with Lossy medium ]V769B
9  
E_low_m2 = 0; \%?8jQ'tX  
E_low_m1 = 0; 3G/ mB  
E_high_m2 = 0; dYew7  
E_high_m1 = 0; >;&V~q:di  
%Initialize Pulse Variables ]7R&m)1
6  
frequency = 700*1e6;% Unit of Mhz @1SKgbt>  
place_pulse = 5; a2=uM}Hsp  
% center_problem_space = max_space/2; 
`_g?y)  
%Set up dielectric medium within the problem space O$umu_  
for i = 1:max_space ':2*+
 
if (i>=dielectric_begin & i <= dielectric_end) Gp3nR<+  
dielectric_space_a(i)=(1-loss_term)/(1+loss_term); 0m YZ7S5g  
dielectric_space_b(i)=0.5/(dielectric_constant *(1+loss_term)); c>WpOZ,  
else "K$Wh1<7  
dielectric_space_a(i)=1; GKsL~;8"  
dielectric_space_b(i)=eta; ~)m t&   
end sHPwW5j/o'  
end NZ+?Ydr8k  
for n = 1:max_time 'oHOFH9:{b  
for k = 2:max_space "G-0iKW;  
E(k) = dielectric_space_a(k)*E(k) + dielectric_space_b(k)*(H(k-1)-H(k)); XG\a-dq[  
end pGb
Fg&  
%Soft Source- adds a value on the grid v!{'23`87  
pulse = sin(2*pi*frequency*delta_t*n); ;GgQ@s@  
E(place_pulse) = E(place_pulse) + pulse; qfP"UAc{/  
%ABC E #9hXZr/8  
E(1) = E_low_m2; #nf%ojh  
E_low_m2 = E_low_m1; 5IE+
M  
E_low_m1 = E(2); fF9oYOh|  
E(max_space) = E_high_m2; +?5Uy
*$  
E_high_m2 = E_high_m1; zr;Y1Xt4  
E_high_m1 = E(max_space-1); lF}$`6  
for j = 1:max_space-1 i h$@:^\  
    H(j) = H(j) +eta*(E(j)-E(j+1)); l;{N/cS  
end ~ut& U  
plot(E) ug6f   
title('Soft Source Simulation with Dielectric Constant = 4') Z>w^j.(  
axis([0 max_space -1.2 1.2]) e"s{_V  
drawnow k"^t?\Q%vI  
end Va/@#=,q]  
9>[.=  
FDTD_2.1 D@rn@N  
LnI{S{]wDh  
Ubw!/|mi  
delta_x = .01;%Set the cell size to 1cm 1l|A[G  
delta_t = delta_x/(2*3e8);%Calculate the time step peTO-x^a-  
max_time = 500; %time is not be limited 0q>NE
<L  
max_space = 200; 2) /k`Na  
E = zeros(max_space,1); %Electric array cxP9n8CuT  
H = E; %Magnetic array ox\B3U%`p}  
D = E; %flux density array 
 fBWJ%W  
I = E; [;IDTo!<>  
dielectric_begin = 100; !8"$d_=h  
dielectric_end = 200; JX\T {\m#  
dielectic_space_a = ones(max_space,1); kTiPZZI  
dielectic_space_b = ones(max_space,1); [`zbf_RyO  
eta = 0.5;
%M;_(jda  
dielectric_constant = 4; n2y/zP>TC  
%Lossy Medium variables - for non-Lossy medium set sigma = 0; wUIsi<Oj  
sigma = 0.04; ej"o?
1l@  
epszero = 8.85419e-12; +Sdx8 Z5  
etaeps = (delta_t*sigma) / epszero; 32bkouq  
%Initalize ABC conditions {Z?$Co^R  
E_low_m2 = 0; +.gf]|  
E_low_m1 = 0; :9x084ESR)  
E_high_m2 = 0; `3sy>GU?  
E_high_m1 = 0; ;oY(I7  
%Initialize Pulse Variables .y;\puNq  
frequency = 700*1e6;% Unit of Mhz hV>4D&<  
place_pulse = 5; r_V
2 J{B  
%Dielectric Medium - wave velocity slows as it travels through the medium UP~WP@0F  
for i = 1:max_space Fyh?4!/.  
if ( i >= dielectric_begin & i <= dielectric_end ) WDoKbTv  
dielectric_space_a(i) = 1/(dielectric_constant+etaeps); u.pKK  
dielectric_space_b(i) = etaeps; p'%: M  
else RP|>&I  
dielectric_space_a(i)=1; =ve*g&  
dielectric_space_b(i)=0; '!yS72{$2  
end {sna)v$;  
end  ENYF0wW  
%Main Loop ]4 K1%ZV  
for n = 1:max_time O
'!r]0Q  
%Loop for D_x ,3J`ftCV  
for k = 2:max_space DQ n`@  
D(k) = D(k)+0.5*(H(k-1)-H(k)); :uIi ?  
end \%-E"[!  
%Soft Source- adds a value on the grid IB#iJ#,  
pulse = sin(2*pi*frequency*delta_t*n); #E$Z[G]  
D(place_pulse) = D(place_pulse)+pulse; }W__ffH  
%Loop for E_x P+;CE|J`X  
for k = 1:max_space-1 MKVfy:g%So  
E(k) = dielectric_space_a(i)*(D(k)-I(k)); *b6I%MZn  
I(k) = I(k)+dielectric_space_b(i)*E(k); [ n0##/  
end M8#*zCp{5  
%ABC E dxkRk#mf:  
E(1) = E_low_m2; k binf  
E_low_m2 = E_low_m1; XYK1-m}2  
E_low_m1 = E(2); q2S!m6!  
E(max_space) = E_high_m2; 2<6`TA*m  
E_high_m2 = E_high_m1; Hn#GS9d_?  
E_high_m1 = E(max_space-1); c+Q.?vJ  
%Loop for H_y Mf;|z0UX  
for j = 1:max_space-1 m<FWv2)^  
H(j) = H(j) +eta*(E(j)-E(j+1)); #4P3xa  
end j*eUF-J1  
plot(E) {XDY:`vZ}  
title('Soft Source Simulation with Dielectric Constant = 4') XoKO2<3  
axis([0 max_space -1.2 1.2]) )DGz`->  
drawnow k"q!|+&Fs  
end

程序代码已经贴在上面了，哪位大侠帮忙看下，这两个程序计算相同的东西为何输出结果却不一样，Sullivan 书上说两个结果应该一样才对呀

好像两叠加系数不一样吧？

什么结果不一样？输出的E波形吗？ |xn#\epy@  
我看源一个是加到E上的，一个是加到D上的，源不一样，出来的电场波形当然有点区别了，但频谱分析下来应该结果是一样的。

输出的E波形不一样，如果要使得输出的E波形一样，我该怎么修改FDTD_2.1这个程序呢

去掉 ^rL_C}YBj-  
*FK`&(B+}  
%Soft Source- adds a value on the grid lwT9~Hyp  
pulse = sin(2*pi*frequency*delta_t*n); D'b#,a;V  
D(place_pulse) = D(place_pulse)+pulse; 2C$R4:Ssw)  
<xo-Fv  
%ABC E 前面加上 -Fxm
si  
%Soft Source- adds a value on the grid .m;G$X|3U  
pulse = sin(2*pi*frequency*delta_t*n); DIaYo4  
E(place_pulse) = E(place_pulse) + pulse; \}5p0.=  
im]g(#GnKh  
试一下看看。

刚试过，输出的E波形还是不对

哦，不知道我Matlab删掉没，没删的话，下班后回去看一下。