Key4hep Discussion

Tuesday 18 Mar 2025, 13:00 → 14:00 Europe/Zurich

32/S-C22 (CERN)

Live Notes

CERN Key4hep Discussion
===

Attendees: 

Apologies:

Date: March 18, 2025

## News

* Summerstudents
    * Justin K: June 2 -- August 29
    * Second project: next round

## Round The Table

### Leonhard

* Working on event selection
    * Root is reading too much and selection takes longer than it should

### Juan

* EPSSU document for Key4hep
    * Added short summaries of components, stack, algorithms, conclusions, FTEs over the years, bibliography
* Test in k4Reco to run k4MarlinWrapper to compare against ConformalTracking
    * Fixed bug in DD4hep's use of material manager for surfaces
        * Check how CLD track reconstrution is affected
            * chi2 changed in percent level
* Porting other processors used in CLDTracking
    * ClonesAndSplitTracker
        * Test needed
    * RefitProcessor
        * Test needed
    * TruthTracker
        * Not yet ported

### Mateusz

* Reading EDM4hep files for Machine learning in python is not working nicely
    * RDataSource is not working
    * podio readers are too slow
    * RDataFrame not supported because of podio::schemaEvolution
        * Could support RDataFrame if we piggy back on ROOT's schema evolution
* Proposed to add CollectionTypeName to all types of collections (links, UserCollection, etc.)
    * Formalise interface of collections so they are all the same, not just by checking of inherited from podio::ColletionBase
* IOSvc:
    * all the documentation, except for some tutorials, is using IOSvc
        * ILD Tutorial working for Mateusz, somebody should cross-check
* How to use Tools with GaudiFunctional?
    * Use Gaudi::PrivateToolHandle
    * Using tools as arguments for operator() works in Gaudi but not via Key4hepFunctional
        * Should also work for conditions
        * Nothing like this is documented anywhere though
* JetReconstruction.jl with static bindings
    * FastJet not so fast in Key4hep as in LCG stacks or build locally
    * At least Julia JetReco not so fast, caching dropped, and difference between two different Julia Projects caused a crash
    * garbage collection only triggered manually
    * Finally JR.jl compiled is slower than c++ fastJet, because of data manipulation

### Andre

* NTR

## AOB
 
* ACAT (September 8--12) Abstract deadline postponed, April 15th, https://indico.cern.ch/event/1488410/abstracts/
* EPS-HEP https://www.eps-hep2025.eu/, April 15th (SIC) abstract deadline
* Venice Symposium

## TODO

- [ ] ILCDirac with switching of OS for ILC VO

## Next Meeting

March 25, 2025

## TODO

 

13:00 → 13:55 Round The Table

Speakers: Andre Sailer (CERN), Juan Miguel Carceller (CERN), Leonhard Reichenbach (University of Bonn (DE)), Mateusz Jakub Fila (CERN), Swathi Sasikumar (CERN)