Hi,
You do not give enough information when describing your problem.
see below
Rene Brun
Vahe Mamyan wrote:
>
> Hello .
> I have Tree h2 in root file whict
> has some branchs, I can't read that
> branchs. For example Trees one branch's name is
> "Event_nr" when I am doing h2->Draw("Event_nr")
> everything is ok, but when I am doing `
>
> Int_t event;
> TBranch *b_Event_nr ;
> h2->SetBranchAddress("Event_nr",&Event_nr);(root file already opened)
I suppose, you meant:
h2->SetBranchAddress("Event_nr",&event);(root file already opened)
or above the declaration should be Int_t Event_nr instead of Int_t event.
In case your Tree was created with something like
MyEvent *event=0;
tree->Branch("event","MyEvent",&event);
where MyEvent class has a member Event_nr, when reading your Tree, you
should do:
myEvent *event = 0;
h2->SetBranchAddress("event",&event);
You should set the address of the top level branch, not the address of a
sub-branch
> b_Event_nr = h2->GetBranch("Event_nr");
> if(!b_Event_nr){ cerr<<"## Error : Can't find branch
> Event_nr"<<endl;exit(1);}
> int nentrys = h2->GetEntries();
> for(int i=0;i<nentrys;i++) {
> b_Event_nr->GetEntry(i); //or h2->GetEntry(i);
> cout<<"Event = "<<Event_nr<<endl;
> }
> I get for for Event_nr wrong numbers like 12001212.
> I am using root Version 3.02/07, my OS is RedHat 6.2
>
> What did I wrong ? Thanks .
>
> Vahe.
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