How can I fit this data by using fit function?

I need to fit the data, I tried to fit it by using gauss fit functions. Can anybody help?

[dpb]

Not w/o data, no...just looking at a picture doesn't let anybody do much of anything.

Need to subtract a baseline and then mayhaps a muti-peak model might have some chance. Looks like interfering peaks may be present, however, which makes things much tougher...

Am familiar with the experiment but never actually did a lab with it to have collected actual data to try to fit...

[Walter Roberson]

My experience suggests that fitting that data well would require 16 to 24 guassians.

Fitting guassians well is difficult to do.Very small changes in proposed position can make a big difference in goodness of fit.

I have long forgotten the details, but when you fit a guassian you need four parameters (ummm, position, half-width, phase, and amplitude it might have been). It turns out that given the right two of those, the other two can be calculated linearly, but I have long forgotten how. The result is that you have to do a nonlinear search for two parameters for each guassian involved, and do a linear calculation at each step, and then calculate the goodness of fit, and then move slightly and try again. Gradient minimization does not work well for the nonlinear search, as it has many many small local minima. A modified simplex search worked better at the time.

Answer 1

[PRABHANSHU PURWAR]

Try these:

https://in.mathworks.com/help/curvefit/curve-fitting.html (Curve Fitting)

http://www.mathworks.com/matlabcentral/fileexchange/23611-peak-fitter(Peakfit)

And few demo files: http://www.mathworks.com/matlabcentral/fileexchange/38006-demo-functions-for-peak-detection-and-fitting (Demo functions for peak detection and fitting)

Hope it helps!!