Mismatch in root file addition

[iamaanand]

I have three root file each has identical branches information. In each file there are two branches named Edep and Edep1 . Now in one method I added three root file by reading this way :
for(Int_t i = 1; i<=3; ++i)
{ string InputFile = “1E6_solid_20_”+to_string(i)+“.root”;
here the spectrum I got

Since these three file has similar info , I tried another method . Taking any one of the file then filling the histogram three times like this way :
for(Int_t i=1;i<=3;i++){
for(Int_t iEntry=0;iEntry<Edep_Branch->GetEntries();iEntry++)
{
Edep_Branch->GetEntry(iEntry);
if(Edep_info!=0)
Edep_his_4pi->Fill(Edep_info);
}
here the spectrum I got

.
Why this mismatch is coming ? Note the no of entries also very much different . Here I added branch named ‘Edep1’ .

But with branch ‘Edep’ this method worked well . No of entries matches also.

I also find problem in overlap this spectrum. First one needed log scale for visualization but second one does not.

[dastudillo]

To merge into one root file, use hadd; to just concatenate on-the-fly (not writing, unless you explicitly save), use a TChain. See this and the TChain docs (or search this forum for examples of both hadd and TChain).