I am a very new root user and have been trying to understand how the TChain works. There is a TTree, called SMT, spread out among four different root files. If I load the first file up using just a straight TFile I can access the data directly like the following: Int_t fdisk01_wedge01_n[768]; SMT->SetBranchAddress("fdisk01_wedge01_n", &fdisk01_wedge01_n); SMT->GetEntry(0); However when I try to load all the data at once with TChain I get very confused. TChain *data_chain = new TChain("SMT"); data_chain->Add("file1"); data_chain->Add("file2"); data_chain->Add("file3"); data_chain->Add("file4"); At this point I can not just run the same code as I did above. Now I ran the makeclass utilities and generated the class files, but now I am even more confused. The variables are declared in the class but only a few are set through the SetBranchAddress functions. But they are all available somehow. I know that this post is very confusing, but I am confused. I have went through the ROOT Users Guide and the examples but they did not help my understanding of this. Any help on this matter would be greatly appreciated. I guess that I just want to know how it works, I could just use the makeclass and close my eyes but that does not put a smile on my face. Justace Clutter
This archive was generated by hypermail 2b29 : Thu Jan 01 2004 - 17:50:14 MET