Hi,
I think this two features should be changed.
1; when creating a TNtuple object with only one variable it gives me
error in filling time. It works fine with more variables.
root [0] TNtuple *ntuple = new TNtuple("ntuple","Demo ntuple","px");
root [1] ntuple->Fill(1.);
*** Break *** segmentation violation
Root >
2; When drawing histogram from an empty TTree or TNtuple object directly to
histogram, it doesn't fill nor create this histogram. I think it should
create some default empty histogram, otherwise I get errors when trying to
work with it. I tried to use empty trees, when there were not any
particles passing detector in the simulation.
Here is interpreter output and corresponding macro
root [2] .x ttree-bug.C
Error: No symbol histo in current scope FILE:ttree-bug.C LINE:12
Error: Failed to evaluate histo->SetTitle("my histo") FILE:ttree-bug.C
LINE:12
Possible candidates are...
filename line:size busy function type and name
// macro demonstrating use of empty ntuple
{
gROOT->Reset();
Int_t nevent=0; // don't generate any events!
TNtuple *ntuple = new TNtuple("ntuple","Demo ntuple","px:py");
for(Int_t i=0;i<nevent;i++) {
ntuple->Fill(gRandom->Gaus(10.,2.5),gRandom->Gaus(0.,0.7));
}
ntuple->Draw("px>>histo");
// I want to work with histogram (here just one example)
histo->SetTitle("my histo");
}
I use version 2.25/03 on Suse Linux.
Miro
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