How can I create a curve that will fit my data?
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The following is my code:(2x2 dataset imported from an excel file, 21 values for y and 21 values for x)
x=dataset1(:,1);
y=dataset1(:,2);
plot(x,y,'Marker','.','MarkerSize',20);
xlabel('Photon Energy(eV)')
ylabel('Harmonic Intensity(a.u.)')
axis square
I am getting this displayed:
But I am trying to plot it like this:
*I tried using the fit and lsqcurvefit but those only gave me best fit lines(unless I used them incorrectly). The closest thing I've got to was inputting S = x(:)\y(:), but that didn't give the same results as the figure.
It's my frist time using MATLAB, let alone programming. Any help would be appreciated.
Accepted Answer
Image Analyst
on 24 Jun 2022
fitnlm in the Statistics and Machine Learning Toolbox, since 2013b, though you should probably upgrade your antique 8 year old version.
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More Answers (1)
Image Analyst
on 24 Jun 2022
I can see from what you did plot that there are not enough points in "dataset" to get the three colored curves that you are hoping to get. You'll need a lot more points.
But if you did, do you have a model for your curve? Perhaps an exponential decay times a cosine wave added to a downward ramp?
y = a1 * exp(a2 * x) .* cos(a3 * x) + a4 * x + a5;
If you have any more questions, then attach your data and code to read it in with the paperclip icon after you read this:
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