[PD] Spectrum graphing amplitude problem
jason at noisybox.net
Mon Oct 22 03:20:02 CEST 2007
Mathieu Bouchard wrote:
> The most rapid change you can have in a signal is an alternance of two
> values: e.g. +1, -1, +1, -1, +1, -1, ... which has S/2 frequency.
Woah, that's a *super* good way to remember that. Thanks. I love
examples, and that's great!
Charles Henry wrote:
>> Any other ideas?
> Another option is to use the 'plot as points' graph. You will get all
> the points that way, even if the size is too small.
I would do that, but the single points are just too hard to see IMO.
> If you're using fft~, you will see the full spectrum from 0 to N-1,
> where the second half of the spectrum is the conjugate of the first
> half. For graphing purposes, you will probably just need the first
That's cool, makes sense. Since I now understand that I'm dealing with
a graph/display issue, maybe I need to do some heavier lifting? That
is, unless somebody can suggest a better way, I guess I'll try and do
block-synchronized snapshots, somehow walk/traverse the fft results
myself and look for local discretized maximums. Doesn't seem like much
The real truth is that although I stand to learn a thing or two by going
down this road, I'm probably just reinventing the wheel and could drop
in an existing spectrum abstraction or external huh?
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