Problem using a string from a tree

[NikkieD]

Dear All,

I’m trying to read a string from a tree so that eventually I can cut it into pieces, because it is a date and time. For some reason, I don’t manage to even print the string on the screen, I can’t figure out how to properly read it from the tree. Here is my code:

#include <iostream>

#include "TList.h"
#include "TTree.h"

const int nFiles = 18;

const char* fileName (int day = 17) 
{
  const char* fileList[nFiles] = {"LT-IVs_testBeam__2019-11-28_17-21.csv",
                              "LT-IVs_testBeam__2019-11-28_17-24.csv",
                              "LT-IVs_testBeam__2019-11-28_17-37.csv",
                              "LT-IVs_testBeam__2019-11-28_22-27.csv",
                              "LT-IVs_testBeam__2019-11-28_22-28.csv",
                              "LT-IVs_testBeam__2019-11-29_10-33.csv",
                              "LT-IVs_testBeam__2019-11-29_18-49.csv",
                              "LT-IVs_testBeam__2019-12-01_09-18.csv",
                              "LT-IVs_testBeam__2019-12-01_18-55.csv",
                              "LT-IVs_testBeam__2019-12-02_23-03.csv",
                              "LT-IVs_testBeam__2019-12-03_06-38.csv",
                              "LT-IVs_testBeam__2019-12-03_17-08.csv",
                              "LT-IVs_testBeam__2019-12-03_17-09.csv",
                              "LT-IVs_testBeam__2019-12-03_19-18.csv",
                              "LT-IVs_testBeam__2019-12-04_14-11.csv",
                              "LT-IVs_testBeam__2019-12-04_15-34.csv",
                              "LT-IVs_testBeam__2019-12-05_17-57.csv",
                              "LT-IVs_testBeam__2019-12-06_21-42.csv"};

  return fileList[day];
}//end const char* fileName

TTree* mergeFiles (int day = 17) 
{
  TList* myList = new TList();
  for (int i=0; i<nFiles; i++)
  {
    TTree* tempTree = new TTree();
    tempTree->ReadFile(Form("/eos/cms/store/group/dpg_tracker_upgrade/BeamTestTelescope/2019-DESY-BT-OT-2S-4MODS/HvMonitoring/%s", fileName(i)));
    myList->Add(tempTree);
    std::cout << "File " << i << " apended to the list, with " << tempTree->GetEntries() << " entries." << std::endl;
  }
  TTree* myTree = TTree::MergeTrees(myList);

  Int_t Index = 0, Year = 0, Month = 0, Day = 0, Hour = 0, Minute = 0, Second = 0;
  char Date;
  Double_t KitV;

  TBranch *bIndex = myTree->Branch("Index",&Index,"Index/I");
  TBranch *bYear = myTree->Branch("Year",&Year,"Year/I");
  TBranch *bMonth = myTree->Branch("Month",&Month,"Month/I");
  TBranch *bDay = myTree->Branch("Day",&Day,"Day/I");
  TBranch *bHour = myTree->Branch("Hour",&Hour,"Hour/I");
  TBranch *bMinute = myTree->Branch("Minute",&Minute,"Minute/I");
  TBranch *bSecond = myTree->Branch("Second",&Second,"Second/I");

  myTree->SetBranchAddress("Date",&Date);
  myTree->SetBranchAddress("KitV",&KitV);

  for (Long64_t i=0; i<myTree->GetEntries(); i++) 
  {
    myTree->GetEntry(i);
    std::cout << Date << " With U " << KitV << std::endl;
    //if (Date.SubString("2019", 0)!=NULL) std::cout << "I found the year" << std::endl;
    Index = i;
    bIndex->Fill();
  }

  return myTree;
}

void hvPlots() {

  TTree* myTree = mergeFiles();
  //myTree->Print();
  //myTree->Scan();
  //myTree->Draw("KitI:Index");

}

An example of what the files looks like is this:

Date/C:KitV/D:KitI/D:M1803V/D:M1803I/D:SF1902V/D:SF1902I/D:M1804V/D:M1804I/D
2019-11-29_10-33-30,-300.0,-7.538000000000001e-07,-300.0,-9.445000000000002e-07,-300.0,-9.247199999999998e-07,-300.0,-8.6902e-06
2019-11-29_10-33-41,-300.0,-7.548700000000001e-07,-300.0,-9.451e-07,-300.0,-9.246499999999999e-07,-300.0,-8.634609999999998e-06
2019-11-29_10-33-51,-300.0,-7.538000000000001e-07,-300.0,-9.449e-07,-300.0,-9.250000000000002e-07,-300.0,-8.676300000000002e-06

Can somebody help me with how to get the string back in some variable so that I can chop it into the year, month and so on?

Cheers,
Nikkie

---

ROOT Version: Not Provided
Platform: Not Provided

[dastudillo]

try these changes:

//...
char Date[40];
//...
  myTree->SetBranchAddress("Date",&Date[0]);

[Wile_E_Coyote]

  myTree->ResetBranchAddresses(); // disconnect from local variables
  return myTree;