find peaks of excel graph

Hello everyone,

I'm having some trouble with finding the peak coordinates of my excel data. The data has x and y values which i graphed, but i used findpeaks(data) and that did not work. I'm trying to have those peaks labeled as well if that is possible. Any help/suggestions are welcomes. Thank you

here is the graphs

here is what my code looks like

% graph
filename = 'HDPE-WAXS.xlsx';
which -all xlsread
DATA1 = readtable('HDPE-WAXS.xlsx');
%dintensity vs 2theta
       
intens = DATA1{:,2};  % intensity
twotheta = DATA1{:,4};  % 2theta

%plot of xrd hdpe
figure(1)
plot(twotheta,intens,'r')
xlabel('2theta (deg)')
ylabel('intensity (couts/sec)')
title('WAXS-XRD of HDPE')

[AH]

You may want to try different options such as NPeaks, MinPeakHeight, ...

If you upload your data, we can provide you with a working syntax.

[Voss]

"i used findpeaks(data) and that did not work"

Do you mean findpeaks(intens)? If that didn't work, you may need to adjust the parameters you specify in the findpeaks call:

https://www.mathworks.com/help/signal/ref/findpeaks.html#namevaluepairs

For more specific help/suggestions, please upload the xlsx file using the paperclip button.

Answer 1

[Cris LaPierre]

I recommend using the Find Local Extrema live task in a live script. It is an interactive way to determine the appropriate settings for the detecting peaks in your specific data set.