I am trying to get some result from a 4D fit. For my fitter I have 19 free parameter. Now the problem is when I switch on MINOS all the parameters positive and negative value are properly calculated except only one parameter positive error is not giving. Interestingly fit status shows successful. I also tried to fit with MINOS switch off then the fitter is working fine. I am also attaching the picture for both cases. I am also using the latest version of the root ROOT 6.25/01. Can you please let me know what can be the possible issues.
I think @moneta can help you.
Hi,
I would need the full log of the Minimization to understand the issue. It could be for example that the parameter is at the limit or the sub-sequent minimization in the N-1 parameter is failing.
Eventually, could you also try with Minuit2, our recommended Minimizer.
Best regards
Lorenzo