I made several Toy experiments generating and fitting according to a certain PDF.
Instead of saving the log file, I saved the RooFitResult in a root file that
later I analyze with a macro.
To minimize in some cases I used
in other cases I used
RooFitResult* r1 = m1.save();
Is there a way to understand from the only RooFitResult which of the two minimization sequences I used ?
in successful fits, in the cases I use hesse, in some cases I get different edm values from what migrad display. Moreover the covariance matrix has some % of uncertainties.
Is there a way to access the covariance uncertainty information from the RooFitResult ?
As a general statement, is it correct to say that a fit is successfull if
the migrad converged, the covariance matrix is definite positive (covQual==3) and edm is small enough (<10-4) ???
Do we really need to inspect the error matrix with hesse or minos to be sure?
Many thanks for any advise