what’s the meaning of the option "ExternalConstraints(…)"
for the member function: “createNLL” of the class RooAbsPdf ?
Let’s say I have p.d.f. and an “ExternalConstraint”
- I perform a fit
- I would like to know the value of the NLL at the minimum
why the “ExternalConstraints(…)” should matter when I compute the value of the NLL ?
Thanks for the clarification.
See the example
root.cern.ch/root/html/tutorials … nts.C.html
for how the constraints are used in RooFit
thanks for your answer.
I think I know how to use constraints for the “fitTo” member function.
What I was asking is why shall I need to specify the constraints in the “createNLL” member function.
In the example you pointed me to, there is no use of “createNLL”.
fitTo calls createNLL with the same options and then just minimize in addition the created nLL.