Handle CAF making when Pandora runs after the NuGraph2 filter

[rtriozzi]

This PR adds a mode governed by the UsePandoraAfterNuGraph FHiCL flag to handle NuGraph2 variables in the CAF maker, when using a second-pass Pandora after filtering noise with NuGraph2, based on work by summer intern Leonardo Lena.

This PR also provides code to fill new NuGraph2 slice-level variables in CAF files.

Relevant information about the NuGraph2 chain is provided in icaruscode PR #868.

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Associated PRs

• Add more NuGraph2 variables to CAFs sbnanaobj#183
• Introduce multi-slice NuGraph2 inference and filtering icaruscode#868

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Review

Tagging for review @acampani and @PetrilloAtWork as reconstruction and infrastructure experts. Thanks a lot!

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Description

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[cerati]

Thanks, overall it looks great -- especially removing the need for the hit mapping makes things much simpler.

The two things I would suggest to change are:

1. Avoid erasing elements from vectors. I think it should be much easier to simply add a check that the element is non-null in the Fill*NuGraph method. Or is there another reason for erasing the elements with null nugraph score?
2. There is no need to get the NuGraph slices from the event if then we just use slices (when UsePandoraAfterNuGraph=true)

[rtriozzi]

I have addressed Giuseppe’s comments (with which I agree). I also added more code to fill some new NuGraph2 CAF variables we developed. I opened the corresponding sbnanaobj PR #183.

[kjplows]

Thanks! @cerati do the changes look good to you?

[cerati]

Please use the NuGraphCategory enum here (and in similar places I might have missed): https://github.com/SBNSoftware/sbnanaobj/blob/develop/sbnanaobj/StandardRecord/SRNuGraphScore.h#L23

[rtriozzi]

Right, thanks! Fixed (and sneaked in some more variables)!

[cerati]

Looks great! I only left a single comment above

[cerati]

Thanks for addressing my comments!

[kjplows]

@PetrilloAtWork sorry to add more to your plate, just bumping this 🙂 -- could you take a look please? Thanks!

[kjplows]

@PetrilloAtWork , @acampani -- could you please take a look at this? Thanks.

[acampani]

I think the changes made here are overall consistent with my expectations and I didn't find anything specific explicitly wrong. I have just a couple of clarifications to ask:
-if the option to run twice Pandora reconstruction (one as input to nu-graph and one after nu-graph, profiting of the semantic classification) is enabled, then nu-graph slices will coincide with the final set of slices produced in the reconstruction so this case is clear;

• if the option to run Pandora reconstruction twice is not selected then nu-graph slices will basically be identical to those Pandora generated in its first (and unique) run with additional features saved at hit-level, correct?
  Then I think the rest of the changes are meant to ensure all the semantic classification output from nu-graph is properly assigned to each slice and later on to each hit (and I guess here the same loop over nu-graph slices is repeated at pfp level because that's where info are stored, i.e. at slice level - I wonder if the second loop over nu-graph slices can be avoided, but perhaps this is not the case and I haven't add a chance to look at the details of this part of the code - could this be quickly checked? since I believe the loop is nested in a way that could allow this).

[acampani]

Also I wonder why slice vertex-related info are highlighted as a change with respect to the previous code version but I hope it's an accident (this info should not have been changed based on nu-graph correct?)

[acampani]

I guess I have only a curiosity on how the TPC wire (tick) distance default is decided (a presentation to look at/a short explanation would suffice for me thanks!)