root files

[J Dutta]

Dear experts,

I want to study a root file directly using the following commands:

root a.root
TBrowser t;

I am getting the following warnings after the first command. This occurs for any root files I use. I do not quite understand this message. Please let me know if I have made any errors in the commands.

Warning in <TClass::TClass>: no dictionary for class LHEFEvent is available
Warning in <TClass::TClass>: no dictionary for class Event is available
Warning in <TClass::TClass>: no dictionary for class GenParticle is available
Warning in <TClass::TClass>: no dictionary for class SortableObject is available
Warning in <TClass::TClass>: no dictionary for class Track is available
Warning in <TClass::TClass>: no dictionary for class Tower is available
Warning in <TClass::TClass>: no dictionary for class Jet is available
Warning in <TClass::TClass>: no dictionary for class MissingET is available
Warning in <TClass::TClass>: no dictionary for class Electron is available
Warning in <TClass::TClass>: no dictionary for class Photon is available
Warning in <TClass::TClass>: no dictionary for class Muon is available
Warning in <TClass::TClass>: no dictionary for class ScalarHT is available

Thanks & Regards,

Juhi

[Michele Selvaggi]

Hi Juhi,

these warnings are simply because ROOT doesn't know Delphes classes by default.
If you do the following the warnings go away (you don't need though):

root -l
root [0] gSystem->Load("libDelphes");
root [1] TFile *_file0 = TFile::Open("delphes_output.root")

Cheers,
Michele

[J Dutta]

Hi,

That worked! Thanks for the reply!

I am looking at the multiplicity(size) distributions of jets, photons and electrons. Is there a way I can vary the binning at this stage without writing a detailed delphes analysis code such as Example2.C?

Regards,

Juhi