LST object build upgrade: change pT5 rz chi2 cut definition into helix approximation

[YonsiG]

PR description:

This PR is to upgrade the LST tracking algorithm. In the pT5 of LST object, we used to used linear approximation for its trajectory in r-z plane. However, a better approximation is that we can treat the pT5 tracks using helix approximation. Place the cut based on keeping 99% true tracks. Slides describing the algorithm can be found here. https://indico.cern.ch/event/1410985/contributions/5931017/attachments/2875400/5035406/helix%20approxi%20for%20pT5%20rzchi2%20new%20results%20versions.pdf

[YonsiG]

/run all

[ariostas]

run all

Since this repo is a fork, it seems like membership is a bit weird so the CI didn't trigger. I might just need to hardcode usernames that can trigger the CI.

[VourMa]

Since this repo is a fork, it seems like membership is a bit weird so the CI didn't trigger. I might just need to hardcode usernames that can trigger the CI.

Just to note that Gavin's command seem to work normally, not sure if his username is explicitly in the sudo list.
Anyways, we can check and fix after you are back from vacations 😃

[YonsiG]

run all

Since this repo is a fork, it seems like membership is a bit weird so the CI didn't trigger. I might just need to hardcode usernames that can trigger the CI.

Should I directly push and create a CMSSW branch, not under my forked repo, so that the CI can be triggered? I think Gavin is pushing to cmssw branch.

[VourMa]

Since this repo is a fork, it seems like membership is a bit weird so the CI didn't trigger. I might just need to hardcode usernames that can trigger the CI

Ah, I see the problem now. SOrry, I misunderstood the initial comment, so this may make sense. However, there is also #44 (comment) which is not explained by this theory.

Should I directly push and create a CMSSW branch, not under my forked repo, so that the CI can be triggered? I think Gavin is pushing to cmssw branch.

I would say finish this PR in the branch that you have, let's not complicate ourselves. In any case, now you can produce your own validation plots. 😉

[slava77]

/run all

[GNiendorf]

@YonsiG Could you please make a comment directly in the code saying what percentile you tuned the chi-squared values to? The reason I ask is because I noticed in other parts of the code slides were linked by other people but some of those links went dead, so all of that info got lost. Also, do you have the script somewhere that you used to tune these chi-squared values from the ntuple? If it's simple enough maybe we shouldn't include it, but I figured I should ask. I don't know what @slava77 and @VourMa think about this.

[slava77]

Also, do you have the script somewhere that you used to tune these chi-squared values from the ntuple? If it's simple enough maybe we shouldn't include it, but I figured I should ask. I don't know what @slava77 and @VourMa think about this.

We discussed this on Monday but postponed the conclusion until the Tuesday meeting and then apparently missed to check/discuss.
Let's get the analysis script available in a SegmentLinking repository.

[VourMa]

/run all

[VourMa]

@YonsiG The code checks failed, please run
scram b -j 12 code-checks >& c.log && scram b -j 12 code-format >& f.log
and apply the change when you commit again.

[github-actions]

The PR was built and ran successfully in standalone mode. Here are some of the comparison plots.

The full set of validation and comparison plots can be found here.

Here is a timing comparison:

   Evt    Hits       MD       LS      T3       T5       pLS       pT5      pT3      TC       Reset    Event     Short             Rate
   avg     46.8    322.8    124.7     48.2     95.3    499.3    133.2    157.2    103.7      2.8    1534.0     987.9+/- 264.7     420.8   explicit_cache[s=4] (target branch)
   avg     44.1    326.1    122.5     48.1     97.8    551.7     89.8    163.3    124.2      2.3    1569.9     974.1+/- 255.1     429.4   explicit_cache[s=4] (this PR)

[github-actions]

The PR was built and ran successfully with CMSSW. Here are some plots.

OOTB All Tracks

The full set of validation and comparison plots can be found here.

[VourMa]

Based on the test output, doesn't it seem like this PR and the target branch have been swapped? @YonsiG could you verify with standalone plots run locally?
@ariostas Should we indeed push Yanxi's PR to the SegmentLinking repo and then make the PR again, i.e. could this be an issue with forks?

[slava77]

Based on the test output, doesn't it seem like this PR and the target branch have been swapped? @YonsiG could you verify with standalone plots run locally?

red (master) in the standalone looks the same as in other technical PRs.
It looks like something is off in this PR (inconsistent with SegmentLinking/TrackLooper#410 )

[ariostas]

Should we indeed push Yanxi's PR to the SegmentLinking repo and then make the PR again, i.e. could this be an issue with forks?

It shouldn't matter that this is from Yanxi's fork. I'll take a look to see what's happening.

[YonsiG]

/run all

[github-actions]

The PR was built and ran successfully in standalone mode. Here are some of the comparison plots.

The full set of validation and comparison plots can be found here.

Here is a timing comparison:

   Evt    Hits       MD       LS      T3       T5       pLS       pT5      pT3      TC       Reset    Event     Short             Rate
   avg     43.6    322.4    122.8     47.0     94.9    500.8    132.6    155.9    105.8      2.0    1527.8     983.5+/- 261.2     418.9   explicit_cache[s=4] (target branch)
   avg     43.7    324.7    122.3     49.2     95.5    500.7    119.1    160.2    105.3      2.0    1522.6     978.3+/- 263.0     416.4   explicit_cache[s=4] (this PR)

[github-actions]

The PR was built and ran successfully with CMSSW. Here are some plots.

OOTB All Tracks

The full set of validation and comparison plots can be found here.

[VourMa]

The PR now looks good to me, thanks @YonsiG! I am approving but I will merge a bit later in case anyone has any leftover comment.

I want to also clarify that merging this PR resolves #42.

[YonsiG]

Thank you @VourMa !