I have met an issue with the ROOT.TFileMerger.
When I set SetFastMethod(True) to merge several files together, it collects only half of the events.
When I use hadd instead, it will show full events(93 events). And when I turn off SetFastMethod to be false, ROOT.TFileMerger collects full events as well.
So could anyone take a look what happened on the SetFastMethod(True)? Actually hard to detect this kind issue and may cause unrealized problems when doing MC/data comparison.
Many thanks!
Hai
ROOT Version: ROOT 6.10/04 Platform: Not Provided Compiler: Not Provided
If you have two files we could use to reproduce the problem, please file a JIRA ticket. I’ve looked at the code, but couldn’t find any obvious place where we could have a bug.
This is a surprising report. hadd uses TFileMerger with (by default) SetFastMethod(True) and thus the 2 things you tried should have been identical. Can you please provide a reproducer so we can resolve this?