Disk Space TLorentzVector

ROOT
1

Hi!

I have a strange problem with storing TLorentzVectors.

I have a root file with px,py,pz,pt and some more information about tracks on reco and truth level.
I tried to store the reco tracks in TLorentzVectors and save them to a new root file for a better handling.
A sample input file is 9.9MB while the output (with the TLorentzVectors only) has 11MB even after discarding all truth information…

Any idea why the needed disc space raises that much? Any chance to avoid that?

Thanks,

Tobias

2

Hi Tobias,

According to your description the disk space need should decrease (due to discarding the truth information). I suspect that the ‘way’ the truth is discarded is not effective and/or you may be call TTree->Fill too much (it should be once per entry, a common mistake is to call it once per track). For more details we would need more specific on how your code does the copy/discarding/etc.

Cheers,
Philippe.