Re: (no subject)

You did not read my mail correctly. I told you to do

    t->SetEntries(nentries);
and not

    t->GetBranch("fEvent")->SetEntries*();

Rene Brun

On Thu, 24 Nov 2005,
Dmitry Naumov wrote:

> Dear Rene,
>
> thank you for this advice. I tried it but it does not read anyway the second
> event:
>
> root [0] TChain *t = new TChain("nuclon")
> root [1] t->AddFile("t1.root")
> (Int_t)1
> root [2] t->AddFile("t2.root")
> (Int_t)1
> root [3] t->GetBranch("fEvent")->SetEntries(2)
> root [4] t->GetBranch("fEvent")->GetEntries() // to check!
> (const Long64_t)2
> root [5] t->GetBranch("fEvent")->GetEntry(0)
> (Int_t)425
> // OK
> root [6] t->GetBranch("fEvent")->GetEntry(1)
> (Int_t)0
> // empty ?!
>
> root Version 5.02/00 Dmitry
>
> Rene Brun wrote:
>
>> Dmitry,
>>
>> Call t->SetEntries(nentries);
>> where nentries is the number of entries if your branches.
>>
>> Rene Brun
>>
>> On Thu, 24 Nov 2005, Dmitry Naumov wrote:
>>
>>> Dear rooters,
>>>
>>> I have a strange problem:
>>> I create TTree with two branches: fRunPars and fEvent.
>>> fRunPars is filled only once and it containes simulation settings
>>> fEvent s filled for each event:
>>>
>>> fTree->GetBranch("fEvent")->Fill()
>>>
>>> Now I created a set of files with these trees. I want to make a TChain of
>>> them:
>>> TChain *t = new TChain("nuclon");
>>> t->AddFile("t1.root"); // has 1 event
>>> t->AddFile("t2.root"); // has 1 event
>>> t->GetEntries(); // gives 0. It is OK because TTree
>>> // has two branches one of which is
>>> filled
>>> // many times, another only once,
>>> thus Entries probably has no sense
>>> t->GetBranch("fEvent")->GetEntries(); // gives 1 ?! Why not 2?
>>>
>>> If I do
>>> t->GetBranch("fEvent")->GetEntry(0); // it is OK
>>> t->GetBranch("fEvent")->GetEntry(1); // this event is empty.
>>>
>>>
>>> Do I misunderstand something? Many thanks in advance, Dmitry
>>>
>
Received on Thu Nov 24 2005 - 15:44:42 MET