Hi, I have an NTuple and I want to do some fast analysis. When I do ntuple->Draw("variable") it draws a nice histogram. How can I get a copy of it? In the following macro I use a trick with cloning histogram htemp created by TNtuple::Draw. However, this is not working for 2D histograms. What is wrong? Is there any way to get a histogram from TNtuple::DrawClone() ? Regards, Miro I'm using version 25_03 for SuSe Linux Macro: { // first generate ntuple TNtuple *ntuple = new TNtuple("ntuple","ntuple","Ehit:yhit"); Double_t Ehit,yhit; for (Int_t i=0;i<100;i++) { Ehit = gRandom->Gaus(10.,0.5); yhit= gRandom->Gaus(0.,0.7); ntuple->Fill(Ehit,yhit); } // plots TCanvas* c1 = new TCanvas("c1","c1",1); c1->Divide(2,2); // trick with 1D histograms c1->cd(1); ntuple->Draw("Ehit"); TH1F * myh1 =(TH1F *) htemp->Clone(); myh1->SetName("myh1"); c1->cd(2); myh1->Draw(); // this works // trick with 2D histograms - doesn't work! c1->cd(3); ntuple->Draw("Ehit:yhit"); TH2F *myh2 = (TH2F *) htemp->Clone(); myh2->SetName("myh2"); c1->cd(4); myh2->Draw(); // it is empty! }
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