{
    TFile *fin = new TFile("example_data.root");
    TNtupleD *nt = (TNtupleD *)fin->Get("nt");
    TH1D *hist2 = new TH1D("hist2","Binned data",100,0.,2.);
    nt->Project("hist2","mass","","",nt->GetEntries()/100);
    
    hist2->SetFillColor(kRed-9);
    hist2->SetStats(false);
    hist2->GetXaxis()->SetTitle("Mass");
    
    TF1 *f1 = new TF1("f1","[0]+[1]*x+[2]*gaus(2)");
    f1->SetParameters(2.,-0.5,3.,1.,0.05);
    hist2->Fit("f1");
}