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<p>Folks,</p>
<p>Please find the minutes <a moz-do-not-send="true"
href="https://halldweb.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_October_30,_2018#Minutes">here</a>
and below.</p>
<p> -- Mark</p>
<p>_________________________________________</p>
<p>
</p>
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<h1 id="firstHeading" class="firstHeading" lang="en"><span
dir="auto">GlueX Offline Meeting, October 30, 2018, </span><span
class="mw-headline" id="Minutes">Minutes</span></h1>
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lang="en">
<p>Present:
</p>
<ul>
<li> <b> CMU: </b> Hao Li, Reinhard Schumacher</li>
<li> <b> FSU: </b> Sean Dobbs</li>
<li> <b> JLab: </b> Ashley Ernst, Mark Ito (chair),
David Lawrence, Simon Taylor, Beni Zihlmann</li>
<li> <b> W&M: </b> Justin Stevens</li>
</ul>
<p>There is a <a rel="nofollow" class="external text"
href="https://bluejeans.com/s/xuYcn/">recording of
this meeting</a> on the BlueJeans site. Use your JLab
credentials to access it.
</p>
<h3><span class="mw-headline" id="Announcements">Announcements</span></h3>
<ol>
<li> <a rel="nofollow" class="external text"
href="https://mailman.jlab.org/pipermail/halld-offline/2018-October/003403.html">New
release of halld_sim: version 3.6.0</a>. Released
October 22. Has changes from Colin Gleason for
amplitude-based generators.</li>
<li> <a rel="nofollow" class="external text"
href="https://mailman.jlab.org/pipermail/halld-offline/2018-October/003405.html">New
bug-fix release: halld_sim 3.1.1</a>. A special
release to get genEtaRegge going.</li>
</ol>
<h3><span class="mw-headline"
id="Review_of_minutes_from_the_October_16_meeting">Review
of minutes from the October 16 meeting</span></h3>
<p>We reviewed <a
href="https://halldweb.jlab.org/wiki/index.php/GlueX_Offline_Software_Meeting,_October_16,_2018#Minutes"
title="GlueX Offline Software Meeting, October 16,
2018">the minutes</a>.
</p>
<ul>
<li> <b>Computing Review</b>. Curtis Meyer has
circulated a list of slide titles he proposes for the
Hall D presentation. David gave feedback. Now only
adding contest remains. </li>
</ul>
<h3><span class="mw-headline"
id="Monitoring_launch_ver_18_.40_NERSC">Monitoring
launch ver 18 @ NERSC</span></h3>
<p>David reviewed <a rel="nofollow" class="external text"
href="https://mailman.jlab.org/pipermail/halld/2018-October/000645.html">his
recent email</a>.
</p>
<ul>
<li> The monitoring launch at NERSC is mostly finished.
There are a few jobs where the 271 thread finished
successfully, but the 272nd won't. This seems to
happen with particular input files. These jobs were
tried on the gluons and ran without a problem.
However, recall that they ran on KNL architecture at
NERSC. David is requesting an interactive node at
NERSC to do a test.</li>
<li> Bryan Hess has found a few more places in the
network where the MTU had room for increase. He is
curious about how the new configuration will perform.</li>
<li> The problem with missing cache files causing jobs
to hang remains, likely due to deletion from the
auto-cache cleaner. David will pursue solutions with
Chris Larrieu.</li>
<li> David is thinking about what to do next. Sean is in
favor of a monitoring launch using 10 files per run
dispersed throughout the Spring 2018 run. David told
Bryan that he is thinking of firing up another launch
at the end of next week.</li>
<li> Beni asked about tape robot problems. David has not
seen any lately, but heavy tape use during data taking
may not have occurred recently.</li>
<li> David and Mark will discuss the version XML file
that David is using on NERSC.</li>
</ul>
<h3><span class="mw-headline"
id="What_I_learned_at_BRNMW_2018">What I learned at
BRNMW 2018</span></h3>
<p>David attended the Basic Research Needs for
Microelectronics Workshop last week. Turns out he
learned quite a lot, from topics like DNA memory
technology to others like hotel meeting room door sound
standards. Please see <a
href="https://halldweb.jlab.org/wiki/images/f/f8/20181030_BRNMW2018.pdf"
class="internal" title="20181030 BRNMW2018.pdf"> his
slides</a> for the details.
</p>
<h3><span class="mw-headline"
id="Events_lost_due_to_vertex_fit_for_Lambda">Events
lost due to vertex fit for Lambda</span></h3>
<p>Hao gave us a detailed look at the problem and proposed
solutions to the issue where kinematic fits with vertex
constraints do not converge. See <a rel="nofollow"
class="external text"
href="https://halldweb.jlab.org/DocDB/0038/003812/001/Offline_software_meeting_Oct_30_HaoLi.pdf">his
slides</a> for the details.
</p>
<ul>
<li> He described the channel where the problem seems
especially severe, γp→ΛΛ̅p.</li>
<li> He sees a deficit in the π<sup>−</sup> lab polar
angle at around 40 degrees, where the yield drops to
nearly zero.</li>
<li> The fits fail when the ROOT linear algebra package
encounters a singular matrix</li>
<li> Two solutions were tried
<ol>
<li> Multiply all matrix elements by 10,000 before
testing the determinant, rescale results back down
as appropriate.</li>
<li> Use tolerance tuning: change the tolerance ROOT
uses to call a determinant "zero". This tolerance
is user settable.</li>
</ol>
</li>
<li> Both methods recover much of the deficit, with
tolerance tuning showing better results.</li>
<li> The fix has been put in a branch (kinFitter_debug)
of halld_recon so other can try it.</li>
</ul>
<p>From the discussion:
</p>
<ul>
<li> Mark worried that the input covariance matrix for
the measured kinematic quantities may have errors.
that lead to this problem. Fixes that give fit
convergence may mask a deeper problem.</li>
<li> Reinhard has done some research on the subject.
Other experiments have encountered similar problems.
Even if there are problems with the covariance matrix
formation, the proposed fixes should remain in place.
They give us a more robust approach to kinematic
fitting in general.</li>
<li> Reinhard also pointed out that having others try
out the fix would answer concerns about the effect on
execution time and precision of results.</li>
<li> Justin suggested trying the branch in the context
of an analysis launch as a test.</li>
</ul>
<h3><span class="mw-headline"
id="CCDB_versions_and_SQLite_file_management">CCDB
versions and SQLite file management</span></h3>
<p>Mark led a discussion prompted by a incident where the
CCDB had errors in one of its calibration sets (a
translation table). From the agenda:
</p>
<ul>
<li> Communication: folks should write to the <a
rel="nofollow" class="external text"
href="https://groups.google.com/forum/#%21forum/gluex-software">Software
Help List</a> when things are broken so others can
avoid problems.</li>
<li> Finding CCDB SQLite backups: to make it easier to
find the backup versions we could create links like
"ccdb_current", "ccdb_yesterday", and/or
"ccdb_last-week".</li>
<li> Move backups to a more obvious place: We could move
the backup version into the same directory as the
latest version, i. e. <a rel="nofollow"
class="external text"
href="https://halldweb.jlab.org/dist/">/group/halld/halldweb/www/html/dist</a>,
which is web-accessible.
<ul>
<li> We could reorganize that directory. There is a
lot of heterogeneous stuff there. Any re-org would
break old webpage links and scripts however.</li>
</ul>
</li>
</ul>
<p>There was actually not a lot of discussion to lead.
People with strong feelings should contact Mark.
</p>
<h3><span class="mw-headline"
id="Review_of_Offline_Work_Packages">Review of Offline
Work Packages</span></h3>
<p>Mark update the list of packages based on discussion
from the last meeting. We took a look at <a
rel="nofollow" class="external text"
href="https://halldweb.jlab.org/wiki-private/index.php/2018_Work_Packages">revised
list</a>. Items now appear in two lists: "Analysis
Software" and "Software Infrastructure". Only the
assignment of volunteers remains to be done.
</p>
<h3><span class="mw-headline"
id="Review_of_recent_issues_and_pull_requests">Review
of recent issues and pull requests</span></h3>
<h4><span class="mw-headline" id="halld_recon">halld_recon</span></h4>
<ul>
<li> <a rel="nofollow" class="external text"
href="https://github.com/JeffersonLab/halld_recon/issues/40">Issue
#40: Sean broke the tracking again...</a> Problem
seen with ρ yield. Sean is looking at it.</li>
<li> <a rel="nofollow" class="external text"
href="https://github.com/JeffersonLab/halld_recon/issues/30">Issue
#30: Trigger monitoring</a> Sean has ideas to help
identify LED triggers that get flagged as physics.</li>
<li> <a rel="nofollow" class="external text"
href="https://github.com/JeffersonLab/halld_recon/pull/43">Pull
Request #43: fix NAN in return value of walk
correction code. Make sure that square root take a
positive value larger than zero</a> Beni eliminated
problem when the ADC amplitude is non-positive.</li>
</ul>
<h4><span class="mw-headline" id="halld_sim">halld_sim</span></h4>
<ul>
<li> <a rel="nofollow" class="external text"
href="https://github.com/JeffersonLab/halld_sim/issues/16">Issue
#16: mcsmear crash</a> There is a problem when RCDB
cannot find a file for two runs from Fall 2016. Sean
filed this as an RCDB issue.</li>
</ul>
<h3><span class="mw-headline"
id="Review_of_recent_discussion_on_the_GlueX_Software_Help_List">Review
of recent discussion on the GlueX Software Help List</span></h3>
<p>We went over <a rel="nofollow" class="external text"
href="https://groups.google.com/forum/#%21forum/gluex-software">the
list</a>. No discussion of note.
</p>
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<pre class="moz-signature" cols="72">--
Mark Ito, <a class="moz-txt-link-abbreviated" href="mailto:marki@jlab.org">marki@jlab.org</a>, (757)269-5295
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