I am facing the following problem:
I am fitting a TH2 histogram with a TF2 function. After the fitting converges I open a root file and I save the TF2 with different ways (the same function that used for the fit, GetFunction from the histo, a new TF2 with same formula and parameters gotten from the fitted TF2).
To save them I simple call the Write function.
My problem is that when I do Eval after the fitting in the code I get different value than the Eval from the objects acquired from the root file (of course same points used for the Eval).
I also notice when I call Dump in both versions (one inside the code that performs the fit and the other from the saved object) I have differences in fFunctor, fContour, fNsave, fSave, fFunctor.*fImpl, fFunctions, fLinearParts…
Am I doing something wrong while writing the TF2 ?
Thank you in advance,