How to normalize tree variables?

Dear All,

I have two trees with some observables to plot and a simple function:

void makePlot(TCanvas *canvas, Int_t numOfPad, const char *name, TTree *mc, TTree *data)
{
    canvas->cd(numOfPad);
    mc->Draw(name, "", "HIST");
    data->Draw(name,  "", "SAMEPE2");
}

to compare mc and data for the observable “name”.
Do you know how to normalize both distributions?

Thank you in advance,
Kaloyan

Modify your logic as indicated below

Rene

void makePlot(TCanvas *canvas, Int_t numOfPad, const char *name, TTree *mc, TTree *data) { canvas->cd(numOfPad); mc->Draw(name>>h_mc, "", "HIST"); data->Draw(name>h_data, "", "SAMEPE2"); TH1 *h_mc = (TH1*)gPad->GetPrimitive("h_mc"); TH1 *h_data = (TH1*)gPad->GetPrimitive("h_data"); double norm = h_data->GetSumOfWeights(); h_mc->SetNormfactor(norm); }