Dear experts,
I created a TF1 with a my (complicated) function, as described in section
" 7.2.2.3 Creating a TF1 with a User Function" here:
https://root.cern.ch/root/htmldoc/guides/users-guide/FittingHistograms.html
Then I configured the Fit with initial values and I fixed two of them:
tf1->SetParameters(pow(10, 6), 100., 0.01, 0.23, 0.23, mass, Bratio);
tf1->FixParameter(5, mass);
tf1->FixParameter(6, Bratio);
at this point I implemented the Fit with the “FRV” options, on a TH1F histogram:
TFitResultPtr fitRes = th1f->Fit("tf1_name", "FRV");
and I obtained the following fit result that seems very good:
however the fit results with very high errors on the parameters, showin the following results (STATUS= NOT POSDEF):
(the full Fit results is here: NEW_S1_rootForum.txt (8.5 KB) )
Can i still accept the result (also if the very high errors)? What should I do to improve the Fit?
I would be very gratefull forn any kind of help.
Thank you a lot
Francesco