Re: Updating a TTree entry

From: Rene Brun <Rene.Brun_at_cern.ch>
Date: Wed, 04 Jul 2007 17:38:47 +0200

We do not support the update of one branch. Instead

  -Create a new Tree with one branch
  -Fill this branch using the values of the old branch
  -Close the file
  -Then use this new Tree as a friend tree of your original Tree (See 

TTree doc)

Rene Brun

Antonio Bulgheroni wrote:
> Dear ROOTers,
> I would like to know if it exists a way to update a TTree entry.
> What I would like to this is more or less the following:
>
> 1. Opening a TTree and properly set the branch address to a local object
> 2. Get the one entry
> 3. Modify the local object containing the branch content
> 4. Updating the branch replacing the current entry with the content of
> the modified local object
> 5. Saving the modified TTree on disk.
>
> I tried with TBranch::Fill but this is adding another event and this
> is not exactly what I want.
>
> Can you help me?
>
> ROOT 5.15/08
> Linux
> gcc (GCC) 4.1.2
>
> Thanks,
>
> Antonio
>
> --
> Antonio Bulgheroni, PhD
>
> Computers have a lot in common with air conditioners:
> Once you open WINDOWS, they stop working properly.
Received on Wed Jul 04 2007 - 17:38:55 CEST