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by dapperdrake 149 days ago
Doesn't FFT depend at least on a "representative" sample of the entire dataset?

Sounds like what makes sql joins NP-hard.

1 comments

No, FFT is perfectly information preserving by definition. Thats why there’s an inverse FFT operation that restores the original signal without any loss (well, modulo accumulated floating point error when working in the discrete instead of symbolic space).