[ROOT] TSelector::ProcessFill(Int_t entry) speed problem

From: Jacek M. Holeczek (holeczek@us.edu.pl)
Date: Tue Apr 16 2002 - 16:25:43 MEST


Hi,
I have met a stupid problem ...
I use TSelector to analyze a disk resident TNtuple.
The TNtuple has a "simple" branch :
	Float_t x;
	TBranch *b_x;
In my "TSelector::ProcessFill(Int_t entry)" I need, however, to access not
only the "entry", but also "entry - 100000" and "entry + 100000" for that 
specific branch :
	b_x->GetEntry(entry); x1 = x;
	b_x->GetEntry(entry - 100000); x0 = x;
	b_x->GetEntry(entry + 100000); x2 = x;
The result is that the analysis ("Process") of the ntuple takes ages ...
Can I somehow speed it up ?
Thanks in advance,
Jacek.



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