[R] Frequency and Phase Spectrograms

Dieter Menne dieter.menne at menne-biomed.de
Thu Dec 6 19:34:19 CET 2007

Todd Remund <tkremund98 <at> hotmail.com> writes:

> I know that there is a function, (spectro3D), that produces the Power
Spectrogram.  Are there R functions
> that produce the Frequency Spectrogram and the Phase Spectrogram?  Thank you
for your time.

fft in stats gives you all you need, possibly combined with some time window in
package signal, which also has some higher level stuff. Do you really want to
interpret the "frequency spectrum" (whatever it is) with real, imaginary part
and signs?

The docs of spectro3D gives makes me cringe:

>>Following Heisenberg uncertainty principle, the short-term Fourier transform
cannot be precised in both time and frequency. >>

I know that's written in quite a few books, but that upside-down thinking has
been a source of confusion for generations of students and professors (of
biology, to say).


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