Why should I use 2 fftshift?

Hello if I have signal x (in time domain).

I saw that sometimes people do fftshift(fft(ffshift(x))). Now, I understand the usage of fftshift to move the DC to the center. But what's the reasoning behind using fftshift twice?

Seems to me that fftshift(fft(x)), should be enough.

Am I missing something here?

Thanks

Answer 1

[Walter Roberson]

You can test it yourself to see if the two are equal.

The magnitudes of the two are equal, but the real and imaginary components are different.

[moose]

thank you.

yes, I saw that the subtraction gives me zero.

so, what's the difference? or, what's the more right way to do it?

I can understand my way fftshift(fft(x)). you're shifting the resulting fft signal.

But, what does it mean, fftshift(fft(fftshift(x)))? it seems that you're first doing the shift on x which is in time domain???