I am currently experiencing a weird problem:
my input files have two entries for my TTree: tree:
tree n has the right number of events, tree (n-1) has LESS events.
When I merge the files the first entry (n-1) is taken and the merged file contains less events than it should.
Is there a way of telling hadd to take only the most recent instance (tree;n)?
Is there also a way to do the same when reading it via a TChain?
In both cases the number n is unknown.
I have two example files located here:
Thanks in advance!
TChain does the right thing. It always takes the tree;n instance.
How can I force ‘hadd’ to do the same or can I use TChain to perform the task ‘hadd’ does?
Which version of ROOT are you using?
I am using version 5.27/06b (comes with the framework) for the creation of the data and 5.28/00b for the analysis.
Another thing I saw: it happens only to bigger files. Files as small as 1MB seem not to be affected whilst files >-50MB have usually more than one tree.
This is quite odd as literally, those version of hadd using a TChain to do the merging. Could you provide a running example showing the problem?
It seems I can’t reproduce the error, neither with the previous version of ROOT I was using (5.22/00d) nor with the ones mentioned above.
I am confused but also happy that it doesn’t occur any more.
However, to be fair I tested only merging two files and no 12 or more as usual.