Entries of a histogram from a TTree

Good morning,

I have a problem with a TTree object.

This Tree contains all the informations about the events collected by a bit complex experimental setup, i.e. a multi-detector sphere.
I’ve created this Tree using a program of analysis, written in C/C++ code.

Thanks to a counter, that is an Int_T initialized to 0 at the starting point, I’ve controlled the number of events registered by an element of my multi-detector.

Then I’ve created a histogram in order to display the distribution of the events respect to the energy for this detector. I generate the TH1F with the Start Viewer : I put the Energy in the X box and I choose the detector, using a condition in the cut box ( the number of the detector is in a branch of my tree).

The problem is that the number of the entries of this histogram is different from that found using the counter, when the program is running.

Sorry if I’ve described the problem in a very confused way.

Thanks in advance.


Could you post your data file as well as the shortest possible RUNNING script explaining your problem?


proof_fusgamma.cxx contains the main part of the script… I hope it’s understandable.

The main parameters in the Tree of the input data files are :

  • fast

  • slow

  • tof

  • numb

  • mulb
    These regards the detector of the sphere, that detect gamma rays.

  • nump

  • mulp

  • enep

  • tofp
    These other branches contain informations about the events collected by other detector, used for heavy ions.

Our aim is to find events generated by a coincidence between the gamma-ray detectors and the heavy ions detectors.

I could explain the dynamics of the analysis in more details, if it is useful for your comprehension.

Thanks a lot.
run89_48ca.root (970 KB)
proof_fusgmma.cxx (11.9 KB)

I requested "the shortest possible RUNNING script "
what you send
-does not compile
-has unsatisfied references to unused functions (init)
-uses many data files

so, let me reiterate my request: please send the SHORTEST RUNNING script reproducing your problem, trying to minimize the number of necessary files to run.
Time to investigate is proportional to the number of lines in your script.


I’m very sorry for these troubles, caused by hurry.

I’ll find a better mode to send the SHORTEST RUNNING script .

Thanks for your patience.