Implement all the variables for the CMS Run 1 AOD Demo

[gordonwatts]

The run 1 demo from CMS makes a final Higgs to 4 lepton plot. Looking through that there are a number of variables that are extracted to make the plot and selections that require some more complex type information than is currently supported by the cms run 1 aod extractor.

This issue is to complete the set of variables required for extraction.

[sudo-panda]

List of variables that need to be supported:

• [x] HitPattern
• [x] GsfElectron

[gordonwatts]

Meeting minutes from a detailed discussion of this...

How to do SelectIndex

Experiment's Datamodel

class Event:
    @property
    def tracks(self) -> Array[Track]

class Track:
    @property
    def pt(self) -> float

    @property
    def hitPattern(self) -> HitPattern

class HitPattern:
    @property
    def nHits(self) -> int

    def getHitPattern(self, i: int) -> int

    def validHitFilter(self, hp: int) -> bool

func_adl Query

Want the track pt's of all tracks with more than 5 valid hits (in the hit pattern mask)

Define events as our source dataset upon which all func_adl queries run (e.g. ObjectStream)

Low level func_adl:

events
    .SelectMany(e: e.tracks())
    .Where(t: Range(0, t.hitPattern().nHits)
                 .Select(nth: t.hitPattern().getHitPattern(nth)))
                 .Where(hp: t.hitPattern.validHitFilter(hp))
                 .Count() > 5
           )
    .Select(t: t.pt())

Comments:

• Do we need support for literals (like zero)?
  • Things like array[0] are supported already, so it should be
  • See visit_Num
• Range specification - def Range(start_index: int, length: int) -> Array[int]
  • Patterned off the LINQ Range
  • Note that Range is a standalone function and source of a stream of objects (which happen to be numbers).
  • In func_adl how is Range defined?
    • def Range(start_index: int, length: int) -> ObjectStream[int]
    • Will have to do from func_adl import Range before you can use this.
    • This is common code for ATLAS and CMS...
    • Implement in C++ as for(index = start_index; index < length; index++) {...}???

Using SelectIndex

events
    .SelectMany(e: e.tracks())
    .Where(t: SelectIndex(t.hitPattern().nHits, nth: t.hitPattern().getHitPattern(nth))
                 .Where(hp: t.hitPattern.validHitFilter(hp))
                 .Count() > 5
           )
    .Select(t: t.pt())

Comments

• SelectIndex isn't a good name for this

If we added SelectIndex:

• Have it as syntatic sugar
• Translated into Range and Select by the short cuts file (similar to aggregate).

LINQ Query:

events
    .SelectMany(e: e.tracks("Tracks"))
    .Where(t: Range(0, t.hitPattern().nHits)
                 .Select(nth: t.hitPattern().getHitPattern(nth)))
                 .Where(hp: t.hitPattern().validHitFilter(hp))
                 .Count() > 5
           )
    .Select(t: t.pt())

C++ Code

Tracks = iEvent.getByLabel("Tracks")

for(auto *t : Tracks) {
    int c =0 ;
    int length = t.hitPattern().nHits();
    int start_index = 0;
    for(int i=start_index; i<length; i++) {
        hp = t.hitPattern().getHitPattern(i);
        if(t.hitPattern().validHitFilter(hp)) {
          c++;
        }
    }

    if(c>5) {
        double p = t.pt();
        ttree->Fill(p);
    }
}

[gordonwatts]

This was done!