Hello !
I am trying to read the variables from a tree (named Tracks), using the
following macro (that I start after having started the tree viewer):
{
tv__tree = (TTree *) gROOT->FindObject("Tracks");
tv__tree_list->Add(tv__tree);
Int_t nhitcot2;
Int_t nhitax2;
Int_t nhitst2;
tv__tree->SetBranchAddress("nhitcot",&nhitcot2);
tv__tree->SetBranchAddress("nhitax",&nhitax2);
tv__tree->SetBranchAddress("nhitst",&nhitst2);
....
}
Then root returns me the following error message :
Error in <TTree::SetBranchAddress>: unknown branch -> nhitcot
Error in <TTree::SetBranchAddress>: unknown branch -> nhitax
Error in <TTree::SetBranchAddress>: unknown branch -> nhitst
When I look in the contents of my tree, doing tv__tree->Print(), I get
the following:
root [1] tv__tree->Print()
******************************************************************************
*Tree :Tracks :
Tracks *
*Entries : 48820 : Total = 3536541 bytes File Size =
3536541 *
* : : Tree compression factor =
1.00 *
******************************************************************************
*Br 0 :_1 :
alg/I:charge/I:d0/F:eta/F:event/I:nhitax/I:nhitcot/I: *
* |
nhitsil/I:nhitsilphi/I:nhitsilst/I:nhitsilz/I:nhitst/I:pT/F: *
* |
paralg/I:phi0/F:run/I:trknum/I:z0/F *
*Entries : 48820 : Total Size= 3515490 bytes File Size =
3515490 *
*Baskets : 110 : Basket Size= 32000 bytes Compression=
1.00 *
I think the suspicious thing is the 0:_1 thing. It look as the variables
are not directly accessible. Actually when I try to access the tree
variables from the browser, I first come to a _1 leave that I have to
open to access the tree variables.
Just another thing: I can for instance plot an histogram directly from
the viewer and then root executes the following command :
tv__tree->Draw("_1.nhitcot","","hist", 48820, 0);
Do you know how I could acces the arguments of the tree in my macro ?
Thanks a lot
Anne-Sylvie
--
-----------------------------------
Anne-Sylvie Nicollerat
office 327-52-56, phone 1-630-840-3899
Fermilab/CDF MS 223 PO box 500,
Batavia, IL 60510 USA
"Pour le croyant Dieu se trouve au debut, pour le physicien au terme de toute pensee." (Planck)
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