RooMCStudy ... bad fits are discarded?

Dear RooFit experts,
This is an important question in order to understand whether we should trust or not the pulls of “RooMCStudy” !

When we run “RooMCStudy” as in the example here :

RooMCStudy* MyToy = new RooMCStudy(*TotalPDF,*x,Extended(true),FitOptions(Minos(true)));

all the fits are retained or just those that did’t fail ?
In other words, when later we want to compute the pulls:
The pulls are computed on ALL the fit results or just on those that ended WITHOUT ERROR ?

If all the fits are retained, how can we tell to RooFit to just retain those that ended WITHOUT ERROR ?


  • Mauro.