since It is impossible for me to merge more than 20K files on the Grid I was thinking about some alternative ways.
Is there the possibility to create a task that read a certain number of root files, containing a TList in which I have some TH1Fs? I would like to have only one output file.
I attach you an example file: this file contains a TList. In the TList I have some TH1Fs, I have 20K of these files.
Thank you very much,
LHC10f6a.root (4.65 KB)
I am not sure what you are looking for. For example this is strictly what you ask for:
hadd -f output.root in1.root in2.root in3.root .... in100.root
i.e. ’ a task that read a certain number of root files, containing a TList in which I have some TH1Fs … only one output file.’