>> You can calculate your tranformation for the input signal S(x_i) once >> And the same transformation for S(x_i)+1 again. > >Won't that just give you the gradient at point x_i, ie. d/dt(S)?
yes. >We are talking about frequency domain aliasing here, oh yeah i see. sorry. > which is when you >generate partials that would be above the nyquist frequencyi, so they get >reflected down into low frequencies. It is not directly related to the >differential of the signal, though a high differential is often indicative >of an aliasing problem. > >Typically you prevent audio aliasing by generating the waveform in a way >so that it contains no partials above nyquist, or by generating it at a >sufficiently high sample rate that there are none, then decimating down. but you can do the pretty same trick for the frequencies: take two different numbers with no common divisors (or just a pair of prime numbers) as sampling rates and see how the output signal changes. The difference give you some linear combination of aliased frequencies. __________________________________________________ Do you Yahoo!? Y! Web Hosting - Let the expert host your web site http://webhosting.yahoo.com/
