[R] Using "R" to find peaks in sampled data
maechler at stat.math.ethz.ch
Tue May 29 16:58:50 CEST 2001
>>>>> "Bill" == Bill Simpson <wsi at gcal.ac.uk> writes:
>> In any case, I have some sampled data that has peaks, and I would
>> like to extract peak height, location, and width, according to
>> almost any statistical model. Gaussian would seem to make the most
Bill> Be specific about the form of your data. Do you mean that you
Bill> have a single variable you measured, and you are talking about
Bill> peaks of some histogram of the data? Or do you have x,y data? If
Bill> the latter, the peak height is just max(y), and the location is
where you might want to use
imax <- which.max(y)
Bill> The width is not too hard; I have a function that finds the FWHM.
which reminds me that S-plus has a function peaks()
that some folks have wanted for R. If anyone has good code,
not stolen from S-plus, but still compatible, please post...
Martin Maechler <maechler at stat.math.ethz.ch> http://stat.ethz.ch/~maechler/
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