Hi Pawel Kraszewski wrote:
> 4. The answer is symmetrical - usually you take only half of it. I > don't > remember the exact difference between the halves, but you may find it > in any > article on FFT. The real part is identical the imaginary part has the opposite sign ("same amplitude, opposite phase"). Jeff Peery wrote: > thanks for the help. I think I'm understanding this a bit better. > although I still don't completely understand the output. here is an > example... for the input I have 1024 samples taken from a 1 Hz square > wave with amplitude = 1. for the output I would expect an infinite > number of frequencies. the output from FFT.fft(myData).real is this: > > . > . > . > -0.498 1 > 0.0 2 > -0.498 3 > 0.0 4 > -0.498 5 > 0.0 6 > -0.498 7 > 0.0 8 Frankly, I don't understand this. After your description I thought your input is like "array([0, 1, 0, ..., 1, 0, 1])". But this can't be. Could you show us how exactly your input array looks like? And how do we have to read your output? Is this a 1d-array? What do the two numbers per line mean? Cheers Christian PS Sorry for the late reply. _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor