{
TFile f ("nbd_test.root");
TCanvas = new TCanvas();
c1->SetLogy();
ntuple1->Draw("N41 >> h1","nch>=30 && nch<=55");
TF1 *fit1 = new 
TF1("fit1","[0]*(TMath::Gamma(x+[1])/(TMath::Gamma(x+1)*TMath::Gamma([1])))*(TMath::Power(([2]/[1]),x))*(TMath::Power((1+([2]/[1])),-x-[1]))");
fit1->SetParameter(0,1.);// normalization constant
fit1->SetParameter(1,20); // k parameter
fit1->SetParameter(2,38.);  // mean multiplicity
h1->Fit("fit1");

TCanvas = new TCanvas();
c1_n2->SetLogy();
ntuple1->Draw("N41 >> h2","nch>=312 && nch<=430");
TF1 *fit2 = new TF1("fit2","[0]*(TMath::Gamma(x+[1])/(TMath::Gamma(x+1)*TMath::Gamma([1])))*(TMath::Power(([2]/[1]),x))*(TMath::Power((1+([2]/[1])),-x-[1]))");
fit2->SetParameter(0,1.);// normalization constant
fit2->SetParameter(1,40); // k parameter
fit2->SetParameter(2,323.);  // mean multiplicity
h2->Fit("fit2");

}