pub fn reconstruct(spectrum: &Spectrum, band: Option<Band>) -> Vec<f64>Expand description
Reconstructs real samples from a spectrum, optionally keeping one band.
The inverse of transform: the normalization it applied is undone bin by
bin, the negative frequencies are rebuilt as conjugates, and the result is
the sample run the spectrum came from. Passing a Band scales each bin by
that band’s coefficient first, which is how a band-limited copy of a signal
is produced without designing a filter.
The answer holds (bins - 1) * 2 samples at the rate Spectrum::rate
reports. A spectrum of fewer than two bins reconstructs to nothing.