Class TChain : public TTree

[berserker]

@pcanal

[quote]It seems that TChain, when it changes file, stops reading values into variable I told him to read into. [/quote]This is unusual and surprising. I would need to see the actual code to diagnose this any further.

Here it is

And excerpt from its’ output. At first, some "Aha"s about the first file: it is possible to have several records with same value in a row, isn’t it? So it is ok. But then we see that file has changed, branch address has changed, but the value doesn’t change anymore!

Aha! 0  input/lhc10d/result_00.root
Aha! 6  input/lhc10d/result_00.root
Aha! 0  input/lhc10d/result_00.root
Aha! 11  input/lhc10d/result_00.root
Aha! 0  input/lhc10d/result_00.root
Wow! 0x21cb830
Current notr 2
Aha! 2  input/lhc10d/result_01.root
Aha! 2  input/lhc10d/result_01.root
Aha! 2  input/lhc10d/result_01.root
Aha! 2  input/lhc10d/result_01.root
Aha! 2  input/lhc10d/result_01.root
Aha! 2  input/lhc10d/result_01.root
Aha! 2  input/lhc10d/result_01.root
Aha! 2  input/lhc10d/result_01.root
Aha! 2  input/lhc10d/result_01.root
Aha! 2  input/lhc10d/result_01.root
Aha! 2  input/lhc10d/result_01.root
Aha! 2  input/lhc10d/result_01.root
Aha! 2  input/lhc10d/result_01.root
Aha! 2  input/lhc10d/result_01.root
<billion of identical messages...>

If I call ->GetEntry() on the chain and not on the branch, I have

Aha! 0  input/lhc10d/result_00.root
Aha! 0  input/lhc10d/result_00.root
Aha! 0  input/lhc10d/result_00.root
Aha! 6  input/lhc10d/result_00.root
Aha! 0  input/lhc10d/result_00.root
Aha! 11  input/lhc10d/result_00.root
Aha! 0  input/lhc10d/result_00.root
Wow! 0x232f450
Current notr 2
Aha! 0  input/lhc10d/result_01.root
Aha! 0  input/lhc10d/result_01.root
Aha! 0  input/lhc10d/result_01.root
Aha! 0  input/lhc10d/result_01.root
Aha! 0  input/lhc10d/result_01.root
Aha! 2  input/lhc10d/result_01.root
Aha! 0  input/lhc10d/result_01.root
Aha! 0  input/lhc10d/result_01.root
Aha! 0  input/lhc10d/result_01.root

So we can see that the value changes!
one.C (973 Bytes)