Problem in RooFit

Hi, everyone!
I’m working on fitting a ROOT file containing data. To make it, I followed the reference RooFit in 20 minutes, but I find that the data in the reference seems to be produced by the p.d.f. (RooDataSet *data = sum->generate(*mes, 2000);)and such way doesn’t suit me. I need to work with the data that is contained in the ROOT file(Bs2JpsiPhiData.root). My problem is how can I fit the pdf I write to the data?
Please help! I’m required to make it immediately!

@StephanH, please can you help here?


You can have a look at the RooFit tutorials here:

rf102 on data import should be your first stop.