Mark Knecht wrote: > I think also that an FFT assumes some sort of longer-term steady state Its actually worse than that. The FFT assumes that the input is steady state periodic with a period length equal to the FFT length. > repetitive nature which isn't in the stock data. The good news is that your stock data isn't much worse of a fit to the assumptions of the FFT than real audio data :-). > I could take a > representative sample - the last 1000 bars, and then treat that as if > it was a repeating cycle and extract frequencies. Then you loose time locality. In music, its not uncommon for the chord to change once every bar. By doing the FFT over 100 bars you are effectively 'averaging' the chord over those 100 bars. Erik -- ---------------------------------------------------------------------- Erik de Castro Lopo http://www.mega-nerd.com/ _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
