Hi Rooters, I have some trouble with chains - I do the following: 1. I have used h2root to make a set of rootfile from ntuples. There are 1436 files. I have used MakeClass to make a class for the tree in the rootfiles. The main of the tree is h1. The name of the class is myclass. 2. In a standalone program, I want to go through as many files as I can using chains. So I do TChain mychain("h1"); mychain.Add("file1.root"); mychain.Add("file2.root"); . . Double_t nevent=mychain.GetEntries(); TTree* mytree=mychain.GetTree(); myclass *event=new myclass(); mychain.SetBranchAddress("b_eventno",&event); /* Note: b_eventno is */ /*branch in tree */ for(int i=0;i<nevent;i++) { mychain.GetEvent(i,1); . . . } The correct data does not show up in event. what am I doing wrong? Two more general questions: 1. MakeClass seems to put every array from the cwm in it's own branch. do I need to do a SetBranchAddress for each one? Is there another way to do MakeClass? 2. What is the ultimate limit to the number of files/events in a chain? I have 1436 files with 150 events. thank you all for you time an effort answering questions. It really makes root work. Peter Fisher MIT Peter Fisher Office 617-253-8561 Professor of Physics Fax 617-253-4100 44-118 MIT email fisherp@mit.edu Cambridge, MA, 02139
This archive was generated by hypermail 2b29 : Thu Jan 01 2004 - 17:50:12 MET