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Re: How 2 extract LOCAL Max? [message #68778 is a reply to message #68776]

Fri, 04 December 2009 04:12

greg.addr
Messages: 160
Registered: May 2007

Senior Member

> Dave_Poreh wrote:
>> Folks
>> I have a signal with few peaks (local maximum). I need to extract the
>> x and y of these Peaks programmatically. The input data is an array
>> whit 2 column (x&y). What is the best way to do this?
>
> "best" is a loaded word...
>
> /A/ way is to move along the array comparing values to their neighbours
> and see if things are going up/down, but you need to be quite careful
> about thresholds that will constitute a real peak (i.e., there can be
> plenty of false peak-lets caused by noise) and account for the fact that
> the signal might not really start to drop for several x increments.

You could apply a boxcar filter (e.g. median) with a width chosen to
exclude your interpretation of noise in the signal (or define your
notion of local), then search for points with adjacent lesser values
(possibly beyond adjacent equal values).

Greg

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[Message index]

		Re: How 2 extract LOCAL Max? By: jeffnettles4870 on Fri, 04 December 2009 11:12
		Re: How 2 extract LOCAL Max? By: greg.addr on Fri, 04 December 2009 04:12
		Re: How 2 extract LOCAL Max? By: Peter Clinch on Fri, 04 December 2009 03:59
		Re: How 2 extract LOCAL Max? By: d.poreh on Wed, 09 December 2009 06:11

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