Merging ROOT files containing different header?

ROOT
1

Dear rooters,

I would like to know if it possible (if it make sense) to merge two root files with different headers (see attached rootfiles)?
By advance
Thank you
cheers
Olivier

PS: I try to do

hadd toto.root ppsim1.root ppsim2.root

and it give this following error :

Target file: toto.root
Source file 1: ppsim1.root
Source file 2: ppsim2.root
Target path: toto.root:/
ppsim1.root tree:Sampler1 entries=1234567890
ppsim2.root tree:Sampler1 entries=1234567890
ppsim1.root tree:Sampler2 entries=1234567890
ppsim2.root tree:Sampler2 entries=1234567890

*** Break *** segmentation violation
/Volumes/MotherShip/geant4/PPSimDev/23628: No such file or directory.
Attaching to process 23628.
Reading symbols for shared libraries . done
Reading symbols for shared libraries … done
0x92a9c189 in wait4 ()

========== STACKS OF ALL THREADS ==========

Thread 1 (process 23628 thread 0x10b):
#0 0x92a9c189 in wait4 ()
#1 0x92a99cd4 in system$UNIX2003 ()
#2 0x008aba61 in TUnixSystem::StackTrace ()
#3 0x008af3e5 in TUnixSystem::DispatchSignals ()
#4 0x008af558 in SigHandler ()
#5
#6 0xc57559c9 in ?? ()
#7 0x00d53bc5 in typeinfo for TStyle ()
Previous frame inner to this frame (gdb could not unwind past this frame)
ppsim2.root (16.6 KB)
ppsim1.root (13.1 KB)

2

hadd can only merge objects of classes deriving from TObject. In your case you have a TString object that cannot be merged. Changed it to a TobjString.
There was a protection missing in hadd in this case. Now protected in the SVN version.

Rene

3

TString to TObjString works perfectly :smiley:
thank you
olivier