Porky wrote:


One of the problems with FFT analysis that we've all overlooked is that we
aren't really dealing with analog waveforms in our simulations, and we can
get erroneous results when using high FFT numbers because we start playing
in the digital "cracks", so to speak,

The FFT gives slightly misleading results due to "edge
effects" or the windows that must be applied to eliminate
them but after windowing, nothing much gets through the
cracks. If we are dealing with signals whose Fourier
components have an integral number of cycles in the length
of the transform and if the signal doesn't contain anything
in the band above half the sample rate than it's exact.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein