fft on an unit matrix

Hello i wanted to try a fft on an unit matrix, but the result of this is very strange.

A has the size 3x3

DFT = fft(eye(size(A)));

The result is:

Whats wrong here ?

[madhan ravi]

why do you think it’s strange?

[Guillaume]

You are aware that fft treats the columns of a matrix independently? There is no such thing as the fft of a matrix.

I'm not sure what you expect from the DFT of a signal with only 3 samples. It's never going to have any meaning anyway. That's nowhere near enough samples to capture any frequency. So what is the point of your trial?

Answer 1

[Alexander Loibl]

When i perform a fft in the terminal for example fft(0) the result is zero and not a complex number