Hi, I am using ROOT from CVS on September 30, 2002, running on Red Hat 7.1. I have run into what appears to be a bug in TChain when using a graphical cut (TCutG). To see if it was a problem just in my code, I went back to the Event example provided in ROOT. I ran the Event example and produced the Event.root file, I then made a copy of Event.root and called it Event2.root so that I could make a TChain with more than one file. I then ran an interactive session of ROOT. root [0] .L libEvent.so root [1] TChain f("T") root [2] f.Add("Event.root") (Int_t)1 root [3] f.Add("Event2.root") (Int_t)1 root [4] f.StartViewer() tv__tree = (TTree *) gROOT->FindObject("T"); tv__tree_list->Add(tv__tree); File name : Event2.root After I started the tree viewer I plotted fNtrack:fNseg. I then made a graphical cut using the editor from the Edit menu, and renamed it cut1. root [5] tv__tree->Draw("fNtrack:fNseg","","", 800, 0); <TCanvas::MakeDefCanvas>: created default TCanvas with name c1 root [5] f.Draw("fNtrack:fNseg","cut1") (Int_t)424 root [6] f.Draw("fNtrack:fNseg","cut1 && fNseg<6000") *** Break *** segmentation violation Notice that when doing f.Draw() with only the graphical cut things work fine, but when an additional selection requirement is added it breaks. I noticed that it seems to break after it has iterated through the first file and breaks when reading the second file. Is this a bug or am I missing something? Thanks Kerry
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