Hi,

I tried to think how to solve this but I don’t have any clue… Here is the situation:

I have a tree and I want to make a copy of all the entries where a specific branch (which is a vector) has at least 2 elements:

This is the branch:

```
*Br 77 :mu_pt : vector<float> *
*Entries : 90155 : Total Size= 1310556 bytes File Size = 270653 *
*Baskets : 20 : Basket Size= 230400 bytes Compression= 4.84 *
```

and for each event in the tree I could have 0 or more entry in the mu_pt vector. So I need to write something like this:

```
TTree* outtree = intree->CopyTree("all events where mu_pt.size()>1");
```

where intree is the original tree and outtree is the new tree.

How can I do that?

Thanks