Move Leaf from a TTree in a file to another file

ROOT
1

Hi,

I have two different files, TMVA_WH_VBF.root and TMVA_WH_VH.root, each file has a tree and a leaf but the name of leaf are different:

TMVA_WH_VBF: tTrain -> NN_VBF
TMVA_WH_VH: tTrain -> NN_VH

I would like to have a single file with both leaves:

ouputfile: tTrain -> NN_VBF
-> NN_VH

I tried various ways but I did not find the solution.
This is only an example of various codes, and I understand why it does not work, but I do not have other idea.

{
  TFile *f1 = TFile::Open("TMVA_WH_VBF.root");
  TTree *T1 = (TTree*)f1->Get("tTrain");

  TFile *f2 = TFile::Open("TMVA_WH_VH.root");
  TTree *T2 = (TTree*)f2->Get("tTrain");
 
  TFile *output = TFile::Open("out.root","RECREATE");
  TTree *outputtree = T1->CloneTree(-1,"fast");

  Float_t NN_VH;
  T2->SetBranchAddress("NN_VH", &NN_VH);
  outputtree->Branch("NN_VH", &NN_VH, "NN_VH/F");

  for(Long64_t j = 0; j < T2->GetEntriesFast(); ++j)
    {
      if ( T2->GetEntry(j) < 0) break;
      outputtree->Fill();
    }

  output->Write();

Thank you
Ciccio

2

Hi,

I think you are just missing: if ( T1->GetEntry(j) < 0) break;

Cheers,
Philippe.