TTree

ROOT
1

Hi, I wanted to create a tree with several branches:

How do I fill the tree for variables for each event, and at the same time variables which are say a sum over one of the event variables?

Thanks Maki

2

If the number of such variables is small compared to the rest of the event, simply declare these variables like event variables. You will consume a bit more space in the tree.
Otherwise you can store your variables inside a “statistic” object, eg a TH1D
and at the end add this or these objects in the Tree header with eg

tree.GetUserInfo()->Add(myhist); and later when reading the Tree, retrieve this object with

TH1D *myhist = tree.GetUserInfo()->FindObject("histoname");
Rene