[Pd] Complex audio signals

[Chuckk Hubbard]

I'm teaching myself some DSP stuff, using Miller's Techniques, a
Digital Filters book, and some other references, and I'm loving it.
I am wondering, though, how one comes up with a complex audio signal
for use in Pd.  I want to experiment with [czero~], and I've also
wondered where complex signals come from for [fft~].
It doesn't seem like it would be possible to create a complex signal
from a real one, but maybe there are ways to synthesize them?

Thanks.
-Chuckk

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