# Extracting entries from a leaf

Hi,
I have a root file with branches within other branches. For example,
the structure is this:
POOLContainer_McEventCollection, which can be cast to a tree, and
within which is the branch:
McEventCollection, and within this branch is another, which isn’t
really a branch, called: DataVectorHepMC::GenEvent
And then it goes:
m_pCont->m_particles_barcodes->second->m_momentum->pp
and in the branch called “pp”, there are leaves which I want to get
the entries of.
In root, I can write the command:
POOLContainer_McEventCollection->Draw(“McEventCollection.m_pCont.m_particle_barcodes.second->m_momentum.pp.dx”),
for example, and it histograms the entries in the leaf called “dx”.
How can I access the individual entries in these leaves?

Thanks

Use TTree::GetV1 as explained in the section “How to obtain more info from TTree::Draw” of TTreePlayer::Draw at

root.cern.ch/root/html/TTreePlay … DrawSelect

Rene

thanks! that worked great.