[Halld-offline] Offline Software Meeting Minutes, July 9, 2014

Wed Jul 9 18:26:17 EDT 2014

Folks,

Find the minutes below and at 
https://halldweb1.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_July_9,_2014#Minutes 
.

   -- Mark
____________________________________________

GlueX Offline Meeting, July 9, 2014
Minutes

    Present:
      * CMU: Paul Mattione, Curtis Meyer
      * FSU: Aristeidis Tsaris
      * IU: Kei Moriya, Matt Shepherd
      * JLab: Alex Barnes, Mark Ito (chair), David Lawrence, Mike Staib,
        Simon Taylor, Beni Zihlmann
      * MIT: Justin Stevens
      * NU: Sean Dobbs
      * UConn: Richard Jones

Announcements

      * [25]CCDB 1.02 has been released. This fixes a problem with the use
        of non-default variations.
      * [26]sim-recon-2014-06-30 has been released. Matt and Paul asked
        about version compatibility for this version. On the farm machines
        at JLab, the following versions were used to build this tag:
           + Xerces 3.1.1
           + JANA 0.7.1p3
           + ROOT 5.34.01
           + CERNLIB 2005
           + gcc/g++/gfortran : 4.4.6 20110731 (Red Hat 4.4.6-3)
           + HDDS 2.1
           + CCDB 1.02

    This information is also contained in the release notes. Matt suggested
    in the future that this be posted on a web page, like the corresponding
    information for [27]Data Challenge 2.
      * Recent automatic tests, both the single track and the b1pi, have
        been failing recently. Mark and Simon are looking into this.

Review of minutes from June 25

    We reviewed the [28]minutes.

EVIO Build

    Mark has succeeded in building EVIO using the source code from the Data
    Acquisition Group's webpage. Use needs to be incorporated into the
    build system.

BCAL Timing

    No new news.

Data Challenge 3

    We validated the sense of the last meeting: we will limit goals to
    analyzing data from tape at JLab and not try to generate a large data
    set suitable for studies. This reduces the amount of preparation needed
    and can be started by the middle of August.

    Generation and reconstruction of EVIO-formatted simulated data is very
    close. David is working on this actively.

Tagger Reconstruction

    Richard led us through his [29]proposal for introducing a random global
    time offset to all events, consistent with the 500 MHz RF time
    structure. This would simulate the real-life uncertainty due to
    event-to-event trigger latency variations and the intrinsic jitter due
    having a fully pipelined data acquisition system driven on a 250 MHz
    clock. At present, all events are analyzed as if the true RF bucket is
    known, a priori. Also the true beam photon energy is also assumed in
    the analysis.

    Tagger hits, including out-of-time accidentals, are already present in
    the simulated data as long as the electromagnetic background is turned
    on. This change means that we would have to use detector information to
    determine both the time and energy of the beam photon of interest, as
    we will have to do for real data.

    This change should not break the current reconstruction, in particular
    since each charged track is reconstructed with its own independent
    starting time. It will require changes to the analysis library, but
    Paul already has a scheme implemented in his analysis library for
    dealing with multiple photon tag candidates; it has just not been
    enabled for GlueX analysis. The scheme includes a [30]parameter for
    setting the time window to use for tag candidates.

    We endorsed the proposal. We thought that it should be made the default
    scheme, but that disabling it should be possible with a FFREAD card in
    HDGeant. In addition the time smearing parameter should be under user
    control.

    Paul and Richard discussed division of labor. Richard will provide a
    set of tagger hit objects and Paul will produce the DBeamPhoton object
    needed for the analysis library. Richard will code up an example of how
    the latter step might go.

    Mark will propose a Subversion strategy for how to manage changes from
    both Richard and Paul without impacting others during development.

Reinstating the Separation between Truth and Hit Information in HDDM

    Richard described the structure in HDDM that we have now where Monte
    Carlo truth information is recorded in parallel with "hit" or
    "detected" information in HDDM in mcsmear. He is implementing these
    schemes for some additional detectors, including the start counter and
    the tagger.

    In the process, he is modernizing the HDDM parsing code to use the C++
    API rather than the original C routines. This gives a major reduction
    in lines of code. Also compression will be done on the HDDM output.

References

   25. 
https://mailman.jlab.org/pipermail/halld-offline/2014-July/001707.html
   26. 
https://mailman.jlab.org/pipermail/halld-offline/2014-July/001710.html
   27. 
https://halldweb1.jlab.org/data_challenge/02/conditions/data_challenge_2.html
   28. 
https://halldweb1.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_June_25,_2014#Minutes
   29. 
https://mailman.jlab.org/pipermail/halld-offline/2014-July/001708.html
   30. 
https://mailman.jlab.org/pipermail/halld-offline/2014-July/001709.html

-- 
Mark M. Ito, Jefferson Lab, marki at jlab.org, (757)269-5295