Dear ROOTers,
I would like to receive some tips or suggestions how to code a non-linear fitting algorithm, starting from the exampleFit3D.C. I have developed a modified version of former that is working properly with n (more than 20) parameters, but when I put one those inside any functions (i.e. inducing a non linear fitting), the program fails before fitting. I am sure I am doing something wrong, but I do not understand where is the problem:
is the TF3 class not supposed to deal with functions with non lineat parameters (like the following examole)?
TF3 * f3 = new TF3("f3","[0] * sin(x) + [1] * cos(y) + [2] * z",0,10,0,10,0,10);
is the wrapping in TF1?
ROOT::Math::WrappedMultiTF1 wf(*f3,3);
or should I just change the type of minimizer from Minuit to some non-linear one, in order to make the
fitter.SetFunction(wf);
able to understand and store my parameters?
I have another question: is the TFormula Class somehow involved in the interpretation of my parameters? If yes how?
Thank you for your patience.
Best regards,
Giammarco Nalin