Trouble making friends with TTrees

I have a TFile with a separate truth and reconstruction TTrees. I have tried to make one a friend of the other so that I can Draw with cuts on the other tree, but it doesn’t seem to be working.

[acas0001] run >> root ZTauTau_5188_lh_Tau1P3P.AAN.root
root [0]
Attaching file ZTauTau_5188_lh_Tau1P3P.AAN.root as _file0…
Warning in TClass::TClass: no dictionary for class AttributeListLayout is available
Warning in TClass::TClass: no dictionary for class pair<string,string> is available
root [1] OS0->AddFriend(“Truth0”)
(class TFriendElement*)0x948f5b8
root [2] OS0->Draw(“ComboMuTau_m”,“Truth0.Muon_N>0”)
TCanvas::MakeDefCanvas: created default TCanvas with name c1
(Long64_t)0

This draws a blank canvas. But if I do OS0->Draw(“ComboMuTau_m”) or Truth0->Draw(“Muon_N”), then I gets plots with entries. I thought maybe nothing passed the cut, but if I logically flip the cut, OS0->Draw(“ComboMuTau_m”,“Truth0.Muon_N<=0”), I still get a blank canvas.

Hi,

Most likely the problem is the same as the one described (and solved) at
root.cern.ch/phpBB2/viewtopic.php?t=6181

In short, if this is an Atlas file, use the tree named ‘CollectionTree’.

Cheers,
Philippe.

Great. Thank you.