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Subject: How to count number of spikes in a signal (related to noise)
Date: Tue, 2 Oct 2007 14:53:09 +0000 (UTC)
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I have a signal which, if no noise is present, looks roughly
like a parabola y = -X.^2. (i.e., x squared)

The ideal signal should be smooth like a parabola. However,
with noise, there can be many jagged spikes in the signal.

I would like to count the number of these spikes. This is
part of my effort to quantify noise in the signal.

Can anyone suggest a good option for counting the spikes in
a signal (in a given range)?

The jagged spikes (noise) can occur along the up and down
slopes or near the top and they can sometimes be very large
- even more than 50% of the amplitude of the parabola.
Individual spikes are usually very narrow as well.