GlueX Offline Meeting, April 20, 2011

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GlueX Offline Software Meeting
Wednesday, April 20, 2011
1:30 pm EDT
JLab: CEBAF Center F326/7


  1. Announcements
  2. Review of minutes from the last meeting: all
  3. Definition of primaries: Beni, Matt, Richard
  4. Action Item Review: all
  5. Review of recent repository activity: all

Communication Information


To connect by telephone:

  1. dial:
  2. enter access code followed by the # sign: 3421244#

Video Conferencing


Talks can be deposited in the directory /group/halld/www/halldweb/html/talks/2011-2Q on the JLab CUE. This directory is accessible from the web at . You have to be a member of the "halld" Unix group to do this.



  • CMU: Curtis Meyer
  • IU: Ryan Mitchell, Kei Moriya, Matt Shepherd
  • JLab: Mark Ito, David Lawrence, Sascha Somov, Simon Taylor, Elliott Wolin, Beni Zihlmann
  • Regina: Andrei Semenov


  • David reported that Nathan Sparks sent an email to Simon and David about track reconstruction problems in cascade events. The current suspicion is that these events may have more curlers that in other topologies studied thus far. The issue is still being studied.
  • Elliott announced that Mark gave a talk at the Online Meeting on a concept for an online conditions database. Mark will present the idea at a future offline meeting.

Review of minutes from the last meeting

We looked over the minutes from the April 6 meeting

  • A tagged version of the calibration data files now exists. See the item under action item review below.

Definition of primaries

Beni described a recent thread on the email list discussing a change he made to HDGeant in order to associate hits with the "true" particles that produced them, especially for the tracking chambers. To do this for non-primary particles he "marked" all particles as primary (with the exception of particles born in the calorimeters) so they would be available in the HDDM output. This caused a problem for others when the distinction between primary and secondary particles no longer obvious. Although there are other ways to re-establish this distinction, we thought we would see if a different way of transmitting the information to the output file could be found, consistent with the original philosophy of what defines primary. Mark will arrange a meeting with Richard Jones and Beni to come up with a solution.

Action Item Review

We looked at the list in the Mantis Bug Tracker.

  • resolved (Mark) Schedule a talk on start counter reconstruction software
    • Note: Talked to Sascha. There is essentially no reconstruction code for the start counter, therefore there is nothing to present.
    • Sascha thought it might be premature to work on this. He thought that the hardware design should settle a bit before starting.
  • resolved (Mark) Form plan for storing monitoring data in CCDB
  • resolved (Mark) Propose scheme for tagging calibration constants
  • resolved (Mark) Mark's build scripts need better documentation
    • Note: Found that there were already a lot of wiki pages dealing with various aspects of these scripts but they were rather weakly linked to the main page. Created a page, linked prominently from the main page, that collects them: Building_and_Using_the_GlueX_Software.
    • Matt commented that the location of the link is not prominent enough. We talked about how the structure of the Offline Software wiki page needs to be updated.
  • resolved (Mark) Look into using "externals" in subversion to coordinate different packages
    • Note: Externals seem aimed at building a single directory structure from a set of separately controlled directories. It is especially important when a particular directory structure is necessary to either build or use the code. We are using calib as a stand-alone directory and in our case we want to retain the ability to mix and match versions of calib and sim-recon. Also the relative position of the calib and sim-recon directories is not critical; it does not require strict enforcement. Further, incorporating calib as a sub-directory of sim-recon is a complication whose need will disappear when a database is used. It would probably be better to avoid this complication and linkage of trees whose purpose is quite different. Simple tagging of calib versions would be simpler and do the job.
  • resolved (David) Review use of STL sort to avoid 80bit/64bit comparison bug
    • Note: A review of the custom comparison functions was done for all of the Hall-D source code. One definite and one potential problem were found. The definite has since been fixed. This was reported at the April 6, 2011 offline software meeting.

Agenda at Collaboration Meeting

We will probably have a similar structure to that used at the the last meeting for the Offline session, with the addition of a talk from Matt on his work on photon reconstruction.

New Action Items

  1. Report on issue with reconstruction in cascade events. --> David, Simon, Nathan
  2. Present the online conditions database at a future meeting. --> Mark
  3. Convene a meeting to write hit-particle correlations to HDDM output from HDGeant. --> Mark