EDM4hep Discussion

Tuesday 24 Nov 2020, 09:00 → 10:00 Europe/Zurich

Vidyo

Live Notes

EDM4hep Live Notes
==================

Date: November 24, 2020
Indico: https://indico.cern.ch/event/978067/

This is a document for taking notes during EDM4hep meetings.

Connected: Tao, Wenxing, Andre, Sang Hyun, Thomas, Clement, Frank, Graeme, Valentin, Joseph, Benedikt, Placido, Pere, Gerri

Apologies:

## Introduction and General Points

## Progress and Discussion

### HSF podio Presentation

* This afternoon, 17:06 CET
    * https://indico.cern.ch/event/941278/contributions/4084844/

## Podio

### Issues

#### CollectionIterator does not fully satisfy iterator concept
* https://github.com/AIDASoft/podio/issues/150
* For const collections, would be useful, e.g. using std::find on the collection

#### Idea: True reference collections
* https://github.com/AIDASoft/podio/issues/146
* remove indirection
* to test if there are performance indications
* FG: use case could be subset collections
* FG: Remove difference between reference collections and non-reference collections
* TM: not clear if collection types can be the same
    * Would be very useful
    * otherwise functions need to be templated; functions based on begin/end to iterators

### PRs
* https://github.com/AIDASoft/podio/pulls

#### CMake handle standard args
* https://github.com/AIDASoft/podio/pull/149
* Review: Andre

#### Disable collection operator=
* https://github.com/AIDASoft/podio/pull/154
* Review: Benedikt

#### Make EventStore non-copyable
* https://github.com/AIDASoft/podio/pull/152
* failing test? spurious? consistent?

### c++ concepts
* BH: add compile time checks for class behaviours: e.g., movable

### Using SIO as backend

* Merged

### issue w/ ROOT and (vectors of) non-copyable collections
* happens in ROOT 6.22
* PM: there is a patch available in LCG repository
    * ROOT team is working on a general solution

### What are the different branches in the root file?

* Related to use in RDataFrame
* Encode more information in the _relation_ branch names?

### Multi-Threading

See minutes of https://indico.cern.ch/event/969468/
--> Open issue(s) for further discussion

* Thomas and Benedikt discussing and started to work, nothing to report yet

#### "event class" in podio

* Currently being perceived

### Meta Data

#### Usage of "metadata" for user defined data
* need to check if current implementation addresses all use cases
* need test use-cases

### Issues following MetaData Developments

* cannot write out event data previously read from file
    * Issue: https://github.com/AIDASoft/podio/issues/103
    * Test: https://github.com/AIDASoft/podio/pull/102
    * TM: have fix, but break framework core handling of collections

* there seems to be a fix in the Gaudi ROOTWriter in FCC-EDM !?
    * historical reason, fixes and developments should be back ported to PODIO
    * ...

#### Writing second file with another tree

* https://github.com/key4hep/K4FWCore/issues/10
* this problem only happens in the GAUDI framework
    * if user tries to write an additional ROOT file
    * to be addressed

### EventStore

### Schema Evolution

- Version for object descriptions, etc.
- Open issue: https://github.com/AIDASoft/podio/issues/86

### Features

* Subset collections?

## LCIOConverters

* k4LCIOReader:
    * https://github.com/key4hep/k4LCIOReader
    * Moved k4LCIOReader code to key4hep project

## EDM4hep
https://github.com/key4hep/EDM4hep/pulls

### Issues

#### k4FWCore: cannot read collections back
* https://github.com/key4hep/k4FWCore/issues/27

### DD4hep output plugin

--> Moving to DD4hep

#### Testing the ddg4 plugin of edm4hep
* LCG stack not working?
* https://github.com/AIDASoft/DD4hep/pull/740
* try basing on dev3/dev4, hsf installation

### Repository is getting too big

* github pages branch is getting large
* Can they be created on the fly?
* Use a different host for the website

### Tracker Hit

* Q: Tracker hit input to tracking algorithms?
* A: In LCIO different traker hits: Planar and Cylindrical using inheritance. Still needs to be adressed how to do this in EDM4hep.
* Q: Is inheritance needed?
* Q: What to use for Driftchambers?
* Open issue:

### Need review of EDM4hepDelphes output

* Output is not stored if no tracks or towers created (?)
    * Allow also other types to be part of the list
    * Allow construction in a more general way (VV)
* Need to assume there is a complete list of reconstructed particles?

* Relations:
    * FCCSW: Issue with more than one RecoParticle pointing to one MCParticle
    * In LCIO to Delphes, conversion happens later than in edm4hep, maybe delphes does de-duplication?
    * TODO: open issue in edm4hep with reproducer (VV)

--> Moving to separate repository

#### Reworking output handling

- TM: better address edge cases
- TM + CH: FCC cases, not sure if delphes or output
- https://github.com/key4hep/k4SimDelphes/pull/5
- TM: How and what to test?
-

### PRs
https://github.com/key4hep/EDM4hep/pulls/

### Release 1.0

* Need:
    * ~~Plugin~~
    * ~~Eventheader~~
    * ~~Meta Data (Event / Run Parameters)~~

## AOB

### Generator infrastructure in FCCSW moved to EDM4hep
* VV: show at next key4hep

### Framework integration of k4SimDelphes

* On hold until delphes output reworked
* Started with updating the Gaudi documentation
    * New cmake in Gaudi v35

### Dual Read-out calorimeter for FCC

* Special data structure used for that simulation
* Tried to use edm4hep, some issues
* Present in a future meeting

### Conditions handling in Belle2
* Benedikt, or Martin Ritter

### Feedback from FCC tutorial for snowmass

* Common question: What are the different branches in the root file?
* ``uproot`` was also used to access the root file
    * Basically re-implemented event store
        * Associations
    * Try to get this into the, e.g., podio repository

### Next meeting:

* December 8, 2020

 

 

09:00 → 09:05 Introduction

Speakers: Andre Sailer (CERN), Frank-Dieter Gaede (Deutsches Elektronen-Synchrotron (DE))

EDM4hep Github

Podio Github

09:25 → 10:00 Discussion

Speaker: Dr All