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Re: How can i get the co-ordinates of the peaks in a plot? [message #50321]

Mon, 25 September 2006 13:29

Paul Van Delst[1]
Messages: 1157
Registered: April 2002

Senior Member

zircola wrote:
> I used max function to get the y value but don't know how to get the
> corresponding x value and how to get the xy value of the more than one
> peaks. please help. thanks:)

Take the derivative (use DERIV) of your curve to locate all the peaks (where the
derivative crosses the zero line. Then, as Mike Braedley's post detailed, use the MAX
function with the optional subscript to get the x value at each zero crossing. You *may*
have to interpolate if the x-axis resolution of your data is too low, but I'd be leery of
doing that.

There's probably an easier way if you use HISTOGRAM. :o)

cheers,

paulv

--
Paul van Delst Ride lots.
CIMSS @ NOAA/NCEP/EMC Eddy Merckx
Ph: (301)763-8000 x7748
Fax:(301)763-8545

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[Message index]

		Re: How can i get the co-ordinates of the peaks in a plot? By: Paul Van Delst[1] on Mon, 25 September 2006 13:29
		Re: How can i get the co-ordinates of the peaks in a plot? By: Braedley on Mon, 25 September 2006 05:05
		Re: How can i get the co-ordinates of the peaks in a plot? By: Tigran Khanzadyan on Mon, 25 September 2006 02:10
		Re: How can i get the co-ordinates of the peaks in a plot? By: zircola on Thu, 28 September 2006 17:45

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