HDGeant4 Meeting, April 23, 2019

From GlueXWiki
Jump to: navigation, search

HDGeant4 Meeting
Tuesday, April 23, 2019
3:00 pm EDT
JLab: CEBAF Center, A110
BlueJeans: 968592007


  1. Review of minutes from the last meeting
  2. Do-over on comparison studies
    1. Particle gun: 2.0 GeV/c pions
  3. Issues on GitHub (all)
  4. Pull Requests on GitHub (all)



  • CMU: Naomi Jarvis
  • JLab: Alex Austregesilo, Thomas Britton, Mark Dalton, Sean Dobbs, Stuart Fegan, Mark Ito (chair), Justin Stevens, Simon Taylor, Beni Zihlmann
  • ODU: Shankar Adhikari
  • UConn: Richard Jones

Review of minutes from the last meeting

We went over the minutes from the April 9th meeting.

  • The issues that stand out from Peter's presentation were the response of the calorimeters to charged hadrons and the difference in efficiency when events are simulated with HDGeant vs. HDGeant4.
  • We still need to answer Carlos Salgado on Issue #101, "Differences between G3 and G4 in eta.pi."

Do-over on comparison studies

Simon showed a few slides, culled from the hundreds of monitoring plots he produced, comparing charged-particle-specific properties of HDGeant vs. HDGeant4. He simulated single 2.0 GeV/c pions generated uniformly in polar angle.

Even in the sample of histograms he showed, which were chosen because of differences seen, the differences are "subtle." Beyond basic understanding of the meaning of the plots on slide three, we did not come up with a mission for further exploration for Simon.

Issues on GitHub

We reviewed all of the open issues for HDGeant4.

  • Reading in # events and source #105 opened 5 days ago by nsjarvis
    • We endorsed Richard's proposal for avoiding confusion in specifying the number of events to be generated and connecting with expectations we have from our experience with HDGeant.
  • Run number read in from two places is confusing #104 opened 5 days ago by nsjarvis
    • Richard explained the hierarchy for specifying run number. It only remains to move the explanation to a more easily found document, perhaps the wiki on GitHub.
  • Skip (in control.in) is ignored #103 opened 5 days ago by nsjarvis
    • This needs to be implemented in HDGeant4 to reproduce the analogous feature of HDGeant.
  • Terminal cleanup? #102 opened 6 days ago by mashephe
    • We endorsed Richard's proposal to introduce a debug level to control verbosity on standard output.
  • Differences between G3 and G4 in eta.pi #101 opened 20 days ago by cwsalgado
    • Thomas pointed out that the problem Carlos saw was due to the lack of the SKIP feature (see Issue #103 above).
  • Calorimeter timing mismatch between g3 and g4 #93 opened on Feb 28 by aaust
    • Still needs investigation.
  • Hit Energy Agreement #89 opened on Feb 26 by ReBarsotti
    • Sean will talk to Rebecca about closing the loop on this issue.

Pull Requests on GitHub

We looked at the most recent pull requests, but they were kind of old. Nothing new there.

Future of the HDGeant4 Meetings

Mark made a proposal, prompted by a conversation he had had with Sean earlier in the day, that we stop having regular HDGeant4 meetings and fold the topics discussed here into Software Meeting agendas. Other ideas were voiced:

  • Wait until we have an HDGeant4 Meeting that only lasts 20 minutes before folding.
  • Expand the scope of the meeting to include general simulation topics, a "Simulation Meeting."

We agreed to think about this some more.