matlab program drawing style

Why the following matlab program can not run the right picture inside the complete waveform, only the right picture waveform half, any elder brother know

clc;clear;
x=load('d1-1.txt');%加载数据
y=load('d1-2.txt');
fs=1e6;
T=1./fs;
L=32768;
t=(0:L-1)*T;
d1=fft(x);d2=fft(y);
D=d1.*conj(d2);
E=abs(D);F=1./E;
%N=length(F);G=F(1:fix(N/2));
H=ifft(F);
figure;plot(t,H);

[Mitchell Thurston]

I'm not sure what you're asking exactly, but in your plot(t,H), the variable t is entirely positive.

Answer 1

[Steven Lord]

Note the scale of the Y axis in your plot. Around t = 0 and t = 0.033 the value of D must get very small in magnitude, leading to 1./E being (relatively speaking) very large. That leads to the Y limits being on the order of 100 rather than on the order of 0.1.

If you were to set the Y axis limits of your plot with the ylim function to the same limits as in your pictures, it might look more like them.

[zhiying]

Y axis is actually not very meaningful for this research, X axis can only be half generated by the above procedure, and the half generated X axis is not symmetrical with the half not generated, so how to draw the negative half axis of X that is not generated? I attached a signal file to this question, could you please try? Help to have a look, thank you!