Finding largest peaks in a graph

Hello!

I am writing a little program to plot out the intensities of split spectral lines from a Zeeman experiment.

I get graphs that look like this:

http://imageshack.us/photo/my-images/267/testvmg.jpg/

I want to be able to find the major peaks of this plot. I've been using

    [pks,locs]=findpeaks(smo);

to find the peaks, but this function finds all of the tiny insignificant peaks. I was thinking of thresholding intensity (i.e. ignoring peaks that are below 5 on the y axis for instance), but I wonder if there is a cleaner way to do this.

Thank you!

Answer 1

[Image Analyst]

As explained in the help, set the 'MINPEAKHEIGHT' property to 5:

[peakValues, indexesOfPeaks] = findpeaks(smo, 'MINPEAKHEIGHT', 5);

or if you really want to set smo to zero below some threshold value, such as 7, you can do this first:

smo(smo<7) = 0;
[peakValues, indexesOfPeaks] = findpeaks(smo, 'MINPEAKHEIGHT', 5);

though I don't think that should be necessary with the data you've shown if you use the MinPeakHeight parameter.