Dear Experts,
I’m trying to minimize my likelihood function, which can be expressed as
and i’m using createNLL():
RooAbsReal* nll = genpdf->createNLL(binnedModel,
RooFit::Extended(true),
RooFit::Offset(true),
RooFit::NumCPU(4));
My question is whether createNLL by default takes into account the N_i! (which is the observed number of events in bin i) term as well or not, because I found that this term can be inserted(Extended-PDF) :
Will enabling RooFit::Extended(true) do this automatically, or does it need to be inserted as described on page 32 of the above document?
The other part of my question is, given that I have 6 parameters to minimize, is there a way to constrain their limits (range) in such a way that all of them show a minimum in the plots of (NLL vs. Parameter)?
PS: The real values of these parameters are known from a given formula, which I have used as starting values in the fit.
Thanks,
Mustapha