ROOT Version: 6.18
Platform: Ubuntu 18.04
I have two root files “tree_1000.root” and “tree_1001.root”, both containing the same type of TTree (“DataTree”).
I can open an interactive session with “
root -l tree_1000.root”
and then plot variables from that tree (e.g. “
DataTree->Draw("Energy")), but what if I want to use the contents of both files to get a plot with more statistics? I tried opening the files with TChain interactively (
TChain* chain = new TChain("tree_1000.root")), but that didn’t work (”
chain->GetTTree()" returns a zero pointer). So how can I do this?
TChain constructor requires tree name, not file name as an argument. This should work:
// Construct the chain
// TChain* chain = new TChain("DataTree");
TChain chain("DataTree") // short version of above
chain.AddFile("tree_100.root"); // Add files using wildcard
You also can merge similar root files with this command in terminal:
$ hadd final.root tree_1000.root tree_1001.root
and then work with 1 file
Thank you very much, both methods you suggested work perfectly now.
This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.