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Re: cepstrum: computing epsilon
On Jun 23, 7:46pm, Laszlo Toth wrote:
> FFT (or, rather, DFT) is a formula that
> converts a series of numbers into another series of numbers. For me.
> (...) Now I see that by
> "Praat fft" you meant "the spectrum analysis facilities (and the belonging
> objects) in the Praat software package".
Exactly. That is the advantage of having a program that models the
physics (like Praat) instead of the mathematics (like Matlab).
Someone complained about the problem of choosing the "epsilon" in
a Matlab implementation of the cepstrum. In a Praat script, you
can express this epsilon in physical units. So if you want to add
white noise with a density of 10^-8 Pascal/Hertz, your cepstrum
routine would be
Formula... if row=1
... then log10 (self[1,col]^2 + self[2,col]^2 + (1e-8)^2)
... else 0 fi
(row one is the real part, row two the imaginary part;
Matlab does have the advantage of doing complex arithmetic less verbosely)
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