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Re: How 2 extract LOCAL Max? [message #68779 is a reply to message #68778]

Fri, 04 December 2009 03:59

Peter Clinch
Messages: 98
Registered: April 1996

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.

If you find a peak then x will be whatever the count increment is and y
will be whatever the value is.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net p.j.clinch@dundee.ac.uk http://www.dundee.ac.uk/~pjclinch/

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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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