[Octave-bug-tracker] [bug #45932] ifft(fft(x)) is not real for x real

[Marco Caliari]

Follow-up Comment #3, bug #45932 (project octave):

I do not think that removing the imag part if small is safe. The problem in
fact is the choice of K. But, there is no heuristic. In xhat of the original
example, xhat(1+i) is exactly equal to conj(xhat(n+1-i)). This should be the
check and the only case in which to apply the zeroing of the imaginary part.

As a second step, I think to remember that there is a proper function in FFTW
to manage this case, which does not compute at all the imaginary part, but
Octave does not use it (at least, when I submitted the report).

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