Hello,
I have a TTree storing different parameters for each event.
The events are filled into the TTree after passing through a preselection module which accepts or rejects events based on certain criteria, say whether a muon above 10GeV is present or not.
My question is, how can I store the actual number of events processed by the preselection module and its efficiency, i.e. (number of events written to tree)/(number of events processed) ?
This is in a sense a global variable for the entire analysis and should be in the Tree header. However, I did not come across any suitable example to do this. How do I go about writing this info to my Tree?
Thanks,
Devdatta.