Tree splitter macro problem

[Geo]

Hello everybody. I found online a macro that splits a given tree with N entries into two identical ones with N/2 entries each. A year ago I used it without any problems but now I don’t seem to get it working.

the macro is:
void splitter(TFile *full_file){

      TTree* full_tree = full_file->Get("mytreecrrct");

      string full_file_name = full_file->GetName();
      int lastindex = full_file_name.find_last_of(".");
      TString rawname = full_file_name.substr(0, lastindex);

      half1_file_name = rawname+"_half1.root";
      half2_file_name = rawname+"_half2.root";

      TFile* half1_file = new TFile(half1_file_name, "RECREATE");
      TTree* half1_tree = full_tree->CloneTree(0);

      TFile* half2_file = new TFile(half2_file_name, "RECREATE");
      TTree* half2_tree = full_tree->CloneTree(0);

      TRandom *r3 = new TRandom3();

      for (int i=0; i<full_tree->GetEntries(); i++){
        full_tree->GetEntry(i);
        Double_t rndm = r3->Rndm();

        if (rndm < 0.5) {
          half1_tree->Fill();
        }
        else {
          half2_tree->Fill();
        }
      }
      half1_file->Write();
      half2_file->Write();

      cout << full_file_name << " entries " << full_tree->GetEntries() << endl;
      cout << half1_file_name << " entries " << half1_tree->GetEntries() << endl;
      cout << half2_file_name << " entries " << half2_tree->GetEntries() << endl;
      cout << "1+2 entries: " << half1_tree->GetEntries() + half2_tree->GetEntries() << endl;
      cout << " " << endl;
    }

void tree_splitter() {

          // had
   TFile* full_file_correctsol_had = new TFile("/afs/cern.ch/work/g/gbillis/TMVA/crrct_sol_total.root","READ");
   splitter(full_file_correctsol_had);

 }

and the output when I compile it in ROOT is :

/afs/cern.ch/work/g/gbillis/TMVA/./tree_splitter.C:26:11: error: cannot initialize a variable of type ‘TTree *’ with
an rvalue of type 'TObject '
TTree full_tree = full_file->Get(“mytreecrrct”);
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/afs/cern.ch/work/g/gbillis/TMVA/./tree_splitter.C:32:4: error: use of undeclared identifier 'half1_file_name’
half1_file_name = rawname+"_half1.root";
^
/afs/cern.ch/work/g/gbillis/TMVA/./tree_splitter.C:33:4: error: use of undeclared identifier 'half2_file_name’
half2_file_name = rawname+"_half2.root";
^
/afs/cern.ch/work/g/gbillis/TMVA/./tree_splitter.C:35:34: error: use of undeclared identifier 'half1_file_name’
TFile* half1_file = new TFile(half1_file_name, “RECREATE”);
^
/afs/cern.ch/work/g/gbillis/TMVA/./tree_splitter.C:38:34: error: use of undeclared identifier 'half2_file_name’
TFile* half2_file = new TFile(half2_file_name, “RECREATE”);
^
/afs/cern.ch/work/g/gbillis/TMVA/./tree_splitter.C:58:12: error: use of undeclared identifier 'half1_file_name’
cout << half1_file_name << " entries " << half1_tree->GetEntries() << endl;
^
/afs/cern.ch/work/g/gbillis/TMVA/./tree_splitter.C:59:12: error: use of undeclared identifier 'half2_file_name’
cout << half2_file_name << " entries " << half2_tree->GetEntries() << endl;

Can anyone help?

[fhoenig]

Try casting the tree, like

TTree *full_tree = (TTree *) full_file->Get(“mytreecrrct”);

[Wile_E_Coyote]

TTree *full_tree; full_file->GetObject("mytreecrrct", full_tree);
if (!full_tree) std::cout << "NO mytreecrrct!" << std::endl;

[ksmith]

FYI:

Getting the same histograms after cuts

Remark on the way to post code snippets: When you post pieces of code on the forum enclose it with ``` . That makes your post much more readable (I systematically edit your posts that way) . So do: ``` // this is a C++ piece of code. ``` And it will display as: // this is a C++ piece of code.

[Geo]

Thank you everybody, the solution was that I missed the (TTree*). Now a new issue occurred. I have a tree that has 36965800 events and when I try to split it, the resulting files come with 2 trees names mytreewrng;27 and mytreewrng;28. The same thing did not happen when I split a much smaller file of 1000 events…anyone has any idea what is happening? I am mentioning the number of events because it is the only difference in the two files.

cheers
George

[Wile_E_Coyote]

Aux;1 aux;2 aux3;

Search for “cycle” and/or “namecycle”, for example in: In a Nutshell: Input and Output . ROOT User’s Guide: Input/Output : Retrieving Objects from Disk , Subdirectories and Navigation . Just for reference: some additional notes about GetObject, Get, FindObjectAny, FindKeyAny, ReadObj, ReadObjAny .