I am trying to fit a couple of mass points in order to extract their sigmas that I will be used for a binning optimization I am using Crystal Ball function to do that
f = ROOT.TF1("fit","[0]*ROOT::Math::crystalball_function(x, [3], [4], [2], [1])",xmin,xmax);
f.SetParameters(1,massPoint,1,10,4 ) # N; alpha, n, xbar, sigma
The issue I am having was is in setting the range of the function. I wonder if there’s any way to do that automatically without having to hard code xmin and xmax of that fit range.
Usually, the fit functions are defined for the same range as the histograms you are fitting. So if hist is your histogram, what about using hist->GetXaxis()->GetXmin() and GetXMax() for xmin and xmax?
I hope I understood your question correctly, otherwise you have to re-explain what you mean with fit range if not the full range of the histogram.
Thanks for your prompt response, and sorry for my delayed answer. I tried your suggestion but I still dont get the result I wish here is an attached screen shoot, I am still fitting with the function as above
