To the use of a TBranch->Fill()

ROOT
1

Hi,

I need to create a program to convert data files from binary format to a root format.
In this program, the data I’m looking for are:

  • a channel number
  • a marker (booleen) on this channel
  • the energy of the hit coded on this channel
  • the time of this hit

So I’ve decided to create a tree with one branch per channel. And in each branch three leaves for the three other parameters (marker, energy and time).
So I have to manipulate a tree with n branches that contains three identical leaves…
If I use the function mytree -> Fill() it will duplicate in each branch the same hit…
So I use mytree->GetBranch(“channel_x”)->Fill() (where x is the number of my channel).

The consequence is at the end of my conversion, if I try to use the TBrowser to visualize my tree its impossible… But if I do it via a routine it works perfectly.
And the use of TChains seems to be impossible…

Did I miss something?

Thank you for your response.

2

By calling TBranch’s Fill directly you do not set the number of entries for the TTree correctly (you could fix that by calling TTree::SetEntries).

[quote]If I use the function mytree -> Fill() it will duplicate in each branch the same hit[/quote]Most likely that is because you set the ‘user object’ address of all the branch to be the same … If you were to have n placeholder (one for each channel/branch) then it should work.

Cheers,
Philippe