How to create a branch like folder in a tree

ROOT
1

Hi, here is a simple question about adding a leaf in a branch. If I do:

TTree *tree=new TTree("myTree","this is a tree"); int v1, v2, v3; tree->Branch("mybranch", &v1, "v1/I:v2/I:v3/I");

So now I create a tree and a branch including v1, v2 and v3. If, I want add another variable, for example v4, under the branch “mybranch”. How do I do that?
If I do,
tree->Branch(“mybranch”, &v4, “v4/I”);
will only create a branch called mybranch only including v4.

Thanks,
Zhiyi.

2

The construct

TTree *tree=new TTree("myTree","this is a tree"); int v1, v2, v3; tree->Branch("mybranch", &v1, "v1/I:v2/I:v3/I");

is not recommended because there is no guarantee that v1,v2,v3 will be in consecutive addresses. It is better to create 4 separate branches.
If you want to create automatically several branches in one call, create a small class with all your variables and pass a pointer to your class
to the TTree::Branch constructor. See examples in the tutorials
and Users Guide.

Rene