[scilab-Users] cepstrum?

[Samuel GOUGEON]

  ----- Message d'origine -----
De : hadi motamedi
Date : 25/10/2010 12:51:
> On 10/25/10, Samuel GOUGEON<Samuel.Gougeon at univ-lemans.fr>  wrote:
>>    Hello,
>>
>> Scilab has a cepstrum() function, with a dedicated help page.
>> Its Scilab's code is editable, whether the help page would not be clear
>> enough.
>> You may also have a look at the Signal processing internal module
>> help Signal processing
>>
>> HTH
>> Regards
>> Samuel
> Thank you for your reply. But it seems that the Scilab 'cepstrum'
> function is not implementing what the cepstrum really sounds in signal
> processing. Please correct me if I am wrong.
Actually, i do not know, i have never used it with Scilab, and its help page 
does not sound
very clear to me (this is why i was advising about editing the script). If we 
refer to the definition
given in Wikipedia (that also tells that there are several definitions)
http://en.wikipedia.org/wiki/Cepstrum#Origin_and_definition
it could be in Scilab, for the power cepstrum:
cs = 4*abs(fft(log(abs(fft(signal))))).^2;
Then, you may adapt it to your needs, whether you need the amplitude cepstrum, 
or another one.
All the required basic functions are here : fft(), log(), abs()...

HTH
Samuel