TChain vs TTree

Laurent Aphecetche (aphecetche@ganil.fr)
Mon, 20 Apr 1998 12:50:04 +0200

Hi,

I would like to transform a program using TTree to a program using
TChain. Basically,
to read my TTree, I do :

TBranch* small = T.GetBranch("small_branch");
TBranch* big = T.GetBranch("the_whole_event") ;

for (Int_t i=0;i<nevent;i++) {
small->GetEvent(i);
if (big->IsNoGood()) continue;
T.GetEvent(i); //read complete accepted event in memory
}

I do not see cleary how this could be done with chains. Should I disable
all branches but the small one, read the event, and then, if ok, enable
the other branches, and read again the same event ?
Or is another way ?

Thanks.

-- 
APHECETCHE Laurent (mailto:aphecetche@ganil.fr)       
GANIL, B.P. 5027, 14076, Caen Cedex 5, France 
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