EDM4hep Live Notes
==================
Date: February 14, 2023
Indico: https://indico.cern.ch/event/1251019/
Connected: Andre, Benedikt, Juan, Nazar, Wenxing, Thomas, Sanghyun, Juraj, Erica, Gerri, Frank
Apologies:
## Introduction and General Points
### Upcoming workshops / conferences
https://github.com/orgs/key4hep/projects/4/views/1
## Progress and discussion
## CEPC Progress on extension for Drift Chamber/ClusterCounting
* See presentation
* https://github.com/key4hep/EDM4hep/pull/179/files
* https://github.com/key4hep/EDM4hep/issues/124
* TPCHit too specific: https://github.com/key4hep/EDM4hep/issues/25
* [ ] Rename TPCHit to TrackerRawData
* [ ] https://github.com/key4hep/EDM4hep/pull/179
* RecDndx
* Make components of VectorMembers (grouping them into appropriate ones)
* Relation to Track; Does it make sense to have the relation to the track?
* In reconstruction track comes first and in analysis the RecDndx information is used
* "Logically" it looks the wrong way around, but in podio philosophy filling information "later" is not currently easily done.
* Do we have to revisit some of EDM4hep in light of the fact that changing quantities after the fact is not possible?
* Could also run collections in parallel (potential issues with filtering)
* Could use external relations/associations (gets cumbersome if there is more than two types involved)
* [ ] Check how this is done in (other) FWs (CMSSW, ATLAS, LHCb, Marlin)
* Should dEdx information be removed from `Track`?
- more general discussion needed on how to deal w/ higher level auxiliary information that is added by a different algorithm
- in EDM4hep modification of data objects not possible after they have been added to a frame
- need to look at solutions by running experiments:
- CMS, LHCb (Benedikt)
- ATLAS (Graeme)
- LCs/Marlin (Frank)
## Dual Readout with small data model extension
* sparse vector:
* https://github.com/HEP-FCC/dual-readout/blob/master/edm4dr.yaml
* What is it used for?
* Used during the digitisation, histogram containing amplitudes in timing window. Used in reconstruction
* objectID could be replaced by relation?
* Would need "untyped" relations, or HitWrapper
* Specialisatoin of RawCaloHitType?
* Discuss in one of the next meeting, or open PR for discussion
## JSON output for EDM4hep
* https://github.com/key4hep/EDM4hep/pull/182
* Updated to use `podio::Frame`
## Store yaml in output files
* https://github.com/AIDASoft/podio/pull/358
* Why convert to json?
* discuss next time or in the PR
## `ddsim` stores its output in `Frames` now (DD4hep >= 1.24)
* https://github.com/AIDASoft/DD4hep/pull/1041
* [ ] Need updates to k4FWCore to be able to read these files
* Need to identify the Gaudi interface to fulfill
## Podio
* https://github.com/AIDASoft/podio/pulls
* https://github.com/AIDASoft/podio/issues
* https://github.com/orgs/AIDASoft/projects/1/views/1
## EDM4hep
* https://github.com/key4hep/EDM4hep/pulls
* https://github.com/key4hep/EDM4hep/issues
## Next meeting:
* February 28, 2023; 09:00 CET