[Scilab-users] Is FPPO available ?

[Stefan Du Rietz]

On 2014-06-04 21:09, Claus Futtrup wrote:
--------------------
> Hi there
>
> I have generated some 60 seconds of (pink) noise, sampled at 48 kHz,
> which I can fft to get a linear-frequency representation
> (predominantly interested in 20 - 20k Hz).
>
> If I plot this data on a log-frequency plot, then of course high
> frequency spectrum plots look very noisy.
>
> I need a fixed-point-per-octave (FPPO) transformation of my data so I
> can study the spectrum better at higher frequencies with a more
> readable trace of my frequency response data. I would be interested in
> for example a 1/3 octave moving-average smoothing.
>
> In effect, the FPPO technique utilizes a measurement time window that
> varies as a function of frequency, utilizing a long time window at low
> frequencies (for narrow frequency resolution) and a successively
> shorter time window at high frequencies (but averaged through the
> entire 60 seconds).
>
> Is FPPO available in Scilab? (Signal Processing Toolbox maybe?) ... I
> cannot find it.
>
> /Claus
>
> P.S. You could see this PDF file for some pictures (go to page 6,
> Figure 4):
> http://www.rationalacoustics.com/files/FFT_Fundamentals.pdf
>
What about wavelets?

Stefan