Extracting entries from a leaf

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:
and in the branch called “pp”, there are leaves which I want to get
the entries of.
In root, I can write the command:
for example, and it histograms the entries in the leaf called “dx”.
How can I access the individual entries in these leaves?


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


thanks! that worked great.