Using Draw with a variable-length array branch

ROOT
1

Does TTree::Draw automatically cut events where a branch in the selection doesn’t have a filled value? Elaboration:

I want to do something like mytree->Draw("mass","mass>=0&&(Added_CharmH_VERTEXCHI2_NEW[0]>0||Added_n_Particles<1)") where mass and Added_n_Particles are not arrays and Added_CharmH_VERTEXCHI2_NEW is an array whose length is Added_n_Particles.

The goal is to draw mass only for events where Added_CharmH_VERTEXCHI2_NEW[0]>0 || Added_n_Particles<1 There are no events where Added_CharmH_VERTEXCHI2_NEW[0]>0 && Added_n_Particles<1
So, the number of events with the OR requirement should be the sum of the number of events with just one of each requirement, right? mass>=0 && Added_CharmH_VERTEXCHI2_NEW[0]>0 yields 280960 events while mass>=0 && Added_n_Particles<1 yields 10 events, but requiring mass && (Added_CharmH_VERTEXCHI2_NEW[0]>0 || Added_n_Particles<1) still yields just 280960 events. In other words, even though 10 events are passing Added_n_Particles<1, they are not getting drawn. What’s going on?

2

Try:
mass && (Added_n_Particles<1 || Added_CharmH_VERTEXCHI2_NEW[0]>0)

3

The result is the same.

4

Try:
mass && (Added_n_Particles>0 && Added_CharmH_VERTEXCHI2_NEW[0]>0)

5

The result is the same. It is also the same with mass>0&&(Added_n_Particles>=0 && Added_CharmH_VERTEXCHI2_NEW[0]>0)

6

If you attach your root file I could try it on my machine.
What ROOT version are you using?
I remember there was a similar problem fixed not so long ago (if I remember well, in some cases, tree branches used in cuts were not properly retrieved).

7

I am using ROOT 6.06/02. I’m afraid the file is 2.8 GB, so I hesitate to try to post it here.