Problems reading a .root file

Hello,

I am having some problems in accessing data in a root file by script.
I know data is there because when I do double-click in the branch icon, using the TBrowser class, I saw the histograms.
The file I need to read is in /castor/cern.ch/atlas/project/larg/g4_cosmic/comm.005003/simul/comm.005003.cosmic.ttr.003001-003200.pool.root.tar
(anyone inside this .tar file).
I need only three informations, they are dx, dy and dz.
They are in the branch: POOLContainer_AthenaVectorCosmicRecord/AthenaHitsVector_TimedTrackRecord/m_hitvector/Position

There are a lot of informations inside this file which need a dictionary, but the information I want dont.

How can I write a macro to access these three variables?

Luciano

[quote]How can I write a macro to access these three variables[/quote]You should try TTree::MakeProxy [See reference Guide] (or MakeSelector, see User’s Guide)

Cheers,
Philippe