I'm confused about the DFT of the data, f(adsbygoogle = window.adsbygoogle || []).push({}); _{n}= cos(3[itex]\pi[/itex]n/N) for n=0,1,...,N. It is definitely an even function, and I read that the fourier coefficients of an even function is real. But when I take the FFT of this in Matlab I get complex numbers, not real numbers. What am I missing?

Thanks !

Reuben

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# Discrete Fourier Transform of Even Function

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