Hi all,
within ROOT 5.26, I have set up a minimizer using the following commands :
ROOT::Math::Minimizer* min = 0;
min = ROOT::Math::CreateMinimizer(“Minuit2”,“Combined”);
fFunc = new ROOT::Math::Functor (this,&VJetEstimation::LikelihoodFunct,7);
min->SetFunction(*fFunc);
min->SetFixedVariable(0,“first name”,1);
…
min->SetVariable(6,“last name”,0.5);
min->Minimize();
min->Hesse();
//min->Minos();
const double *param = min->X();
const double *err = min->Errors();
I declare the functor as a function of 7 parameters but in fact, some of them are just indexes used to choose among several options (different mathematical expressions in fact). Therefore they are used as “min->SetFixedVariable” but when I cout their value (*param) and their associated errors (*err), I see that the error is always assign to 10% of the parameter value. Then, I would to know if the fact that I use this way to specify some fixed parameters affects the minimization of my function and the calculation of the errors on the “real” free parameters of my function.
Many thanks in advance for your help.