Again on TTreeeReaderArray and TVector3

[afilippi]

Hi all,
I apologize to re-open a topic that was already discussed, for instance in these two threads:

Number of entries in a tree

I have a tree which I’m analysing using MakeClass. I’ve modified the .C file so it reads a branch, event by event, and fills out a histogram. Judging by the number of entries in that histogram, it seems that I’m doing something wrong. The histogram has 1.24e07 entries. What confuses me is that when I plot the same branch in TBrowser, the number of entries in that histogram is 63287. Can someone explain me why is that so? The file I’m using, together with .C and .h files, is here. https://drive…

Reading a sub-branch of array of TArrayD objects

Hi Gia, The makeClass mode (which you seem to be using) does not support reading the content as object (like a TArrayD). To read this file, you can use the skeleton produced by MakeProxy or if you are using v6 by MakeSelector or by using TTreeReader. Cheers, Philippe.

I’m experiencing the same issue but cannot find a way to solve it.

I produced a tree via geant4_vmc (Example02 with a few tweaks, not on the root output though: a few tracks per event, several hits per track). I’m trying to read the information on hits via TTreeReaderArray, which works pretty well when I need to retrieve an array of numbers (say, TTreeReaderArray<Double_t>), but fails when the array to be retrieved is made of TVector3’s: I just get nonsense numbers (10e-312), and the length of the TVector3 array I get is zero as well, very similar to the issue discussed in the first of the threads mentioned above.
Drawing the TVector3 components works fine, so I guess the issue is related to how TTreeReaderArray handles the array of TVector3 hits.
I am running root v6.12/06 on centOs7, compiled with gcc 4.8.5. The piece of code I am using to inspect the Tree content has been produced via MakeSelector (MakeClass does not work either).

Is there any update with respect to the suggestions quoted in the mentioned threads?
Were the TVector3 contained in a TClonesArray collection as suggested (which I’m not aware of, and I cannot get any hint about), is there a way to retrieve the correct information?

I attach the root file causing the issue: https://drive.google.com/open?id=1eEK2Oyf_0S1bTXCCfB0j26XvS-PG-_je

Thanks, cheers
Alessandra

[oshadura]

@pcanal maybe you can recommend something here?

[afilippi]

never mind, I solved the issue by including in the tree as separate leaves the components of the TVector3 I wasn’t able to resolve. Not elegant, but effective.