Re: [ROOT] Reading TChain into memory

From: Rene Brun (Rene.Brun@cern.ch)
Date: Tue Dec 10 2002 - 16:25:38 MET


Hi Mike,

This problem was fixed a few weeks in the development version.
This will appear in our coming release 3.04/01 shortly.

Rene Brun

On Mon, 9 Dec 2002, Mike Miller wrote:

> Hi all, I have another problem reading a series of TTree objects as a
> TChain in compiled code (root 3.03.09).  I have a tree in each file and
> that tree has 4 branches, I read 3 of the 4 branches.  I have explicitly
> deactivated the one branch I don't read and activated the 3 branches I do
> read.  I've verified that I use SetBranchAddress correctly and the the
> information I read into memory is fine.  The problem is that the call to
> TChain::GetEntry(int, int) dies on the last entry of the first file in the
> chain.  The first file has 2657 entries, so I'm assuming that means that
> entries [0,2657) are valid, so that a call to GetEntry(2657) should get
> the 0th entry of the second file.  If I use TChain::GetFile() to look at
> the pointer to the current file, I see that the file pointer isn't
> changing until I call GetEntry(2658).  Does this mean that the valid range
> is [0,2657]?
> 
> Regardless, if I try to read more than one branch at a time, i get a 
> seg-fault when I cross the boundary between the first and second file 
> in the TChain.  This used to work for me in an older root version 
> (3.02.0x).  How can I fix this?  Thanks, Mike
> 
> -- 
> Michael L. Miller (Yale Physics) michael.miller@yale.edu
> 
> Seattle:	206.543.2908	EPE group, 2nd floor physics.
> BNL: 		631.344.8342	Building 118 Yale Software
> Yale:   	203.432.6615	Room 301 WNSL
> 



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