[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 .. nlc.u}#  
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两个都是1D的？ R0ID2:i]F  
代码贴出来？

FDTD1D_1.5 ::Ke^dp  
m8'C_U^89  
FuI73  
delta_x = .01;%Set the cell size to 1cm r.3/
F[.  
delta_t = delta_x/(2*3e8);%Calculate the time step NI#X@  
max_time = 500;% time is be limited -p3Re9  
max_space = 200; Bjk]ZU0T  
E = zeros(max_space,1); fVb-$  
H = E; kt`nbm|aw  
dielectric_begin = 100; ];.pK  
dielectric_end = max_space; '!l1=cZD  
dielectic_space_a = ones(max_space,1); 4wC+S9I#E^  
dielectic_space_b = ones(max_space,1); J)P$2#  
eta = 0.5; i1H\#;`$  
dielectric_constant = 4; _^Mx>hb4.  
etaeps = eta/dielectric_constant;
.ObZ\.I  
%Lossy Medium variables - for non-Lossy medium set sigma = 0; I}Nd$P)>  
sigma = 0.04; _ZY)M  
epszero = 8.85419e-12; hxCvk/7sT  
loss_term = (delta_t*sigma) / (2*epszero*dielectric_constant); 'smWLz}  
%ABS needed for LHS of problem space do not work with Lossy medium 8} =JKR^cK  
E_low_m2 = 0; ?A(QyaKz  
E_low_m1 = 0; n6s}ww)  
E_high_m2 = 0; 6-?66gmT  
E_high_m1 = 0; !r#?C9Sq  
%Initialize Pulse Variables ylt`*|$  
frequency = 700*1e6;% Unit of Mhz w"R:\@ F  
place_pulse = 5; aW>6NDq(  
% center_problem_space = max_space/2; PaV-F_2  
%Set up dielectric medium within the problem space sB;@>NY  
for i = 1:max_space CPNL 94x  
if (i>=dielectric_begin & i <= dielectric_end) KII
*az  
dielectric_space_a(i)=(1-loss_term)/(1+loss_term); V(Ub!n:j  
dielectric_space_b(i)=0.5/(dielectric_constant *(1+loss_term)); '1M7M(va  
else C@th O  
dielectric_space_a(i)=1; %Gt.m  
dielectric_space_b(i)=eta; dtpoU&?6s  
end .'Y]R3\M+  
end u_ABt?'  
for n = 1:max_time M5xCC!  
for k = 2:max_space H$I=W>;  
E(k) = dielectric_space_a(k)*E(k) + dielectric_space_b(k)*(H(k-1)-H(k)); Z!hafhcX  
end V}\~ugN)y  
%Soft Source- adds a value on the grid FQ=@mjh  
pulse = sin(2*pi*frequency*delta_t*n); **}h&k&%2  
E(place_pulse) = E(place_pulse) + pulse; 6/rFHY2q  
%ABC E HttiX/2~  
E(1) = E_low_m2; zbq@pj)Qu  
E_low_m2 = E_low_m1; xO-+i\ ZV  
E_low_m1 = E(2); lo[.&GD  
E(max_space) = E_high_m2; "~D]E7Q3y  
E_high_m2 = E_high_m1; wE~V]bmtW  
E_high_m1 = E(max_space-1); =}.EY iD  
for j = 1:max_space-1 E9~Ghx.  
    H(j) = H(j) +eta*(E(j)-E(j+1)); 9W(dmde>  
end rF]h$Z8o  
plot(E) o865(<p  
title('Soft Source Simulation with Dielectric Constant = 4') Th=eNL]  
axis([0 max_space -1.2 1.2]) #5V9oKM  
drawnow TY1I=8  
end qAw x2fPu  
$sEy%-  
FDTD_2.1 'Fm
vu  
?Wz8[u  
eopD5  
delta_x = .01;%Set the cell size to 1cm L'F<ev  
delta_t = delta_x/(2*3e8);%Calculate the time step {?yr'*  
max_time = 500; %time is not be limited j$+nKc$  
max_space = 200; `QXErw  
E = zeros(max_space,1); %Electric array :s4p/*f  
H = E; %Magnetic array t+eVR8  
D = E; %flux density array l8?>>.<P=  
I = E; b[`Yi1^]%g  
dielectric_begin = 100; b j'Xg  
dielectric_end = 200; Z?\2F%  
dielectic_space_a = ones(max_space,1); B[KJR?>  
dielectic_space_b = ones(max_space,1); ELj\[&U  
eta = 0.5; M%@!cW  
dielectric_constant = 4; Dc_yM  
%Lossy Medium variables - for non-Lossy medium set sigma = 0; lyGhdgWc  
sigma = 0.04; &uO%_6J  
epszero = 8.85419e-12; [D!jv"  
etaeps = (delta_t*sigma) / epszero; d+'p@!W_  
%Initalize ABC conditions ariLG [:X  
E_low_m2 = 0; nJo`B4'U  
E_low_m1 = 0; NUp<e%zB  
E_high_m2 = 0; rwI  
E_high_m1 = 0; ;72T|e  
%Initialize Pulse Variables vMS |$L  
frequency = 700*1e6;% Unit of Mhz YxP&7oq  
place_pulse = 5; Y*UA,<-  
%Dielectric Medium - wave velocity slows as it travels through the medium uXKERzg  
for i = 1:max_space UXh9:T'%  
if ( i >= dielectric_begin & i <= dielectric_end ) (2=Zm@Zpf  
dielectric_space_a(i) = 1/(dielectric_constant+etaeps); !TUrQ  
dielectric_space_b(i) = etaeps; ,gS;m &!'J  
else L|,!?cSAT  
dielectric_space_a(i)=1; ={z*akn,  
dielectric_space_b(i)=0; h-%R<[  
end C_7+a@?B  
end PbmDNKEh{  
%Main Loop |]c8jG\h  
for n = 1:max_time ia MUsa{  
%Loop for D_x v-PXZ'7~  
for k = 2:max_space o|$AyS{1  
D(k) = D(k)+0.5*(H(k-1)-H(k)); O<,\^[x  
end e:5bzk!~  
%Soft Source- adds a value on the grid |cR;{Z8?_  
pulse = sin(2*pi*frequency*delta_t*n); *FMMjz  
D(place_pulse) = D(place_pulse)+pulse; A -b [>}_  
%Loop for E_x !7kG!)40  
for k = 1:max_space-1 9pX&ZjYP-  
E(k) = dielectric_space_a(i)*(D(k)-I(k)); w'm;82V:P-  
I(k) = I(k)+dielectric_space_b(i)*E(k); lR(+tj)9uO  
end 'hs2RSq  
%ABC E 3de_V|%  
E(1) = E_low_m2; w/kt3Lw  
E_low_m2 = E_low_m1; PF53mUs4  
E_low_m1 = E(2); "OdXY"G  
E(max_space) = E_high_m2; *3?'4"B{8  
E_high_m2 = E_high_m1; pim!.=vN/U  
E_high_m1 = E(max_space-1); q,+yqrt  
%Loop for H_y HB
MhtfWW  
for j = 1:max_space-1 F~P%AjAx'  
H(j) = H(j) +eta*(E(j)-E(j+1)); 'JRvP!]  
end x= 5N3[5  
plot(E) (Kv#m 3~  
title('Soft Source Simulation with Dielectric Constant = 4') xLC3>>P  
axis([0 max_space -1.2 1.2]) 1A\OC  
drawnow aP/T<QZ~  
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？ ]Ccg`AR{  
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 uoX:^'q   
O]1y0BOQ  
%Soft Source- adds a value on the grid e0T34x'
  
pulse = sin(2*pi*frequency*delta_t*n); YYu6W@m]  
D(place_pulse) = D(place_pulse)+pulse; OG~6L4"  
-/g B|J  
%ABC E 前面加上 %|o
J>+  
%Soft Source- adds a value on the grid t 0|
!(3  
pulse = sin(2*pi*frequency*delta_t*n); 'F$l{iR  
E(place_pulse) = E(place_pulse) + pulse; s1h/}  
b/{t|io{  
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。