Automatic Complex Conjugate in ftt

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Ha Oe
Ha Oe on 26 Nov 2019
Commented: Ha Oe on 26 Nov 2019
So I am computing the fft of an array containing vectors. The documentation says that the fft treats each collumn as a vector and computes the fft of each collumn. This means that the following should be the same:
% F1 and F2 should be equal
data = rand(4,100)
F1 = fft(data')' ; % F1
F2 = zeros(size(data)) ;
for n = 1:4
F2(n,:) = fft(data(n,:)) ; % F2
end
But they are not equal. In fact, F2 is the complex conjugate of F1. Does anyone know why this is this happening?

Accepted Answer

David Goodmanson
David Goodmanson on 26 Nov 2019
Hello Ha Oe
the quote command is not just the transpose, it's the complex conjugate transpose (Hermetian conjugate). For the straight transpose, use .' (dot quote).

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