I have some questions about the ROOT.Math.Minimizer.
So, if I understood correctly the least squares (or Chi2?) are minimized here, is that correct?
Then, I found online that one should use the numerical (default) precision ROOT.Math.MinimizerOptions.SetDefaultPrecision(1e-16) and not a value below or above, is that right?

Thanks a lot in advance and cheers!

Welcome to the ROOT forum

I think @moneta can help you with this question.


The Minimizer class can minimise any function and his includes the Chi2 function. If you have a set of data points, you can also use the ROOT::Fit::Fitter class which will create internally for you the Chi2 function. See ROOT: ROOT::Fit::Fitter Class Reference.