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<p>Computers,</p>
<p>Please find the minutes below and at
<a class="moz-txt-link-freetext" href="https://halldweb.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_February_1,_2017#Minutes">https://halldweb.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_February_1,_2017#Minutes</a>
.</p>
<p> -- Mark</p>
<p>_______________________</p>
<h2><span class="mw-headline" id="Minutes">Minutes</span></h2>
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<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">Present:</p>
<ul style="list-style-type: square;">
<li><b>CMU</b>: Naomi Jarvis, Will McGinley</li>
<li><b>FIU</b>: Mahmoud Kamel</li>
<li><b>JLab</b>: Thomas Britton, Mark Ito (chair), Peter
Pauli, Nathan Sparks, Simon Taylor, Beni Zihlmann</li>
<li><b>MIT</b>: Maria Patsyuk</li>
<li><b>Regina</b>: Tegan Beattie</li>
<li><b>UConn</b>: Richard Jones</li>
<li><b>W&M</b>: Justin Stevens</li>
</ul>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">There is a<span
class="Apple-converted-space"> </span><a rel="nofollow"
class="external text"
href="https://bluejeans.com/s/LIDGf/" style="color:
inherit !important; background: transparent; padding:
0px !important; text-decoration: inherit !important;">recording
of this meeting</a><span class="Apple-converted-space"> </span>on
the BlueJeans site.</p>
<h3 style="break-after: avoid; font-weight: bold;"><span
class="mw-headline" id="Announcements">Announcements</span></h3>
<ul style="list-style-type: square;">
<li><b><a rel="nofollow" class="external text"
href="https://mailman.jlab.org/pipermail/halld-offline/2017-January/002601.html"
style="color: inherit !important; background:
transparent; padding: 0px !important;
text-decoration: inherit !important;">New releases
of hdds and sim-recon: hdds-3.9, sim-recon-2.11.0</a></b>.
The release came out on January 24. See the link for the
announcement.</li>
<li><b><a rel="nofollow" class="external text"
href="https://mailman.jlab.org/pipermail/jlab-scicomp-briefs/2017q1/000133.html"
style="color: inherit !important; background:
transparent; padding: 0px !important;
text-decoration: inherit !important;">New SciComp
Web Portal</a></b>. The<span
class="Apple-converted-space"> </span><a
rel="nofollow" class="external text"
href="http://scicompnew.jlab.org/" style="color:
inherit !important; background: transparent; padding:
0px !important; text-decoration: inherit !important;">new
site</a><span class="Apple-converted-space"> </span>is
in beta release now. SciComp is soliciting feedback on
the page. There is a "Suggestion" button at the top of
the page for your convenience in doing so.</li>
</ul>
<h3 style="break-after: avoid; font-weight: bold;"><span
class="mw-headline"
id="Review_of_minutes_from_the_last_meeting">Review of
minutes from the last meeting</span></h3>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">We went over<span
class="Apple-converted-space"> </span><a
href="https://halldweb.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_December_21,_2016#Minutes"
title="GlueX Offline Meeting, December 21, 2016"
style="color: rgb(85, 34, 0); background: transparent;
padding: 0px !important; text-decoration: underline;">the
minutes from the meeting on January 18</a>.</p>
<ul style="list-style-type: square;">
<li><b>Backups of the RCDB database in SQLite</b>. Mark
reminded us that we cannot use an SQLite database if it
is sitting on a Lustre file server. It must be copied to
a non-Lustre disk first. Unfortunately, the backup
location, /cache/halld/home/gluex/rcdb_sqlite/, on
Lustre so that it will get written to tape
automatically. (The directory is part of the
write-through cache.)</li>
<li><b>Lustre Recovery</b><span
class="Apple-converted-space"> </span>is complete.
They were able to restore 4 of the 5 OSTs that had been
corrupted. Files that remain that cannot be accessed
will not be coming back.</li>
</ul>
<h3 style="break-after: avoid; font-weight: bold;"><span
class="mw-headline"
id="A_wrapper_for_signal_MC_generation">A wrapper for
signal MC generation</span></h3>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">Thomas has written a wrapper for
generation of signal Monte Carlo data. The script does
event generation (genr8), detector simulation (hdgeant),
and signal smearing (mcsmear) with the input of a minimal
set of parameters. Several people have private approaches
to this problem, but this is an attempt to consolidate
approaches. Other generators will be added in the future.</p>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">For now the script can be found in
the sim-recon git repository, in
src/programs/Utilities/MCwrapper. We discussed whether we
should change it to the hd_utilities repository; the
matter will be addressed offline.</p>
<h3 style="break-after: avoid; font-weight: bold;"><span
class="mw-headline" id="Collaboration_Meeting_Agenda">Collaboration
Meeting Agenda</span></h3>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">We looked at the current state of the
offline section of the<span class="Apple-converted-space"> </span><a
href="https://halldweb.jlab.org/wiki/index.php/GlueX-Collaboration-Feb-2017"
title="GlueX-Collaboration-Feb-2017" style="color:
rgb(85, 34, 0); background: transparent; padding: 0px
!important; text-decoration: underline;">collaboration
meeting agenda</a>:</p>
<h4 style="break-after: avoid; font-weight: bold;"><span
class="mw-headline" id="Saturday_February_18.2C_2017">Saturday
February 18, 2017</span></h4>
<ul style="list-style-type: square;">
<li>9:00 Session IIb (100) ---
Analysis/Offline/Calibration - (Organizer: Sean Dobbs) -
Chair: -
<ul style="list-style-type: square;">
<li>9:00 (25) --- Offline Software Status -- Mark Ito</li>
<li>9:20 (25) --- Calibration Status -- Sean Dobbs</li>
<li>9:40 (20) --- Offline Data Processing ---
Alexander Austregesilo</li>
<li>10:00 (20) --- HDGeant4 Update --- Richard Jones</li>
<li>10:20 (20) ---</li>
</ul>
</li>
</ul>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">If you have suggestions, contact
Mark.</p>
<h3 style="break-after: avoid; font-weight: bold;"><span
class="mw-headline" id="HDGeant4_Status">HDGeant4 Status</span></h3>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">Richard sent out<span
class="Apple-converted-space"> </span><a rel="nofollow"
class="external text"
href="https://mailman.jlab.org/pipermail/halld-offline/2017-January/002610.html"
style="color: inherit !important; background:
transparent; padding: 0px !important; text-decoration:
inherit !important;">an email</a><span
class="Apple-converted-space"> </span>yesterday
summarizing progress on HDGeant4. He notes in closing that
"HDGeant4 is now mature enough to pass into production."</p>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">At the meeting he told us that
development is done; all essential features have been
implemented.</p>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">He showed details of the comparisons
he has used to both expose issues with HDGeant (HDG3) and
drive development of HDGeant4 (HDG4) that rely on the
MCTrajectories that give verbose, step-by-step information
about particle propagation. He turned off production of
secondary particles to facilitate comparison.</p>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">The build of HDG4 has fixes to the
vanilla Geant4 distribution that fixes bugs. He urged us
to take advantage of those fixes (as happens naturally in
the build).</p>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">He compared the total track length of
particles produced in three particles: photons, neutrons,
and others. The numbers are comparable in the HDG3/HDG4
comparison, but there is about twice as much total track
length in HDG4, due mainly to neutrons being propagated
down to lower energy.</p>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">The total number of particles was
shown in three categories: photons, electrons, and others.
There are only about 30% more particles in HDG4, but the
proportion of photons increases from 25% for HDG3 to 50%
for HDG4 due to lower cut-offs in the photon simulation.
Conversely, electrons go from 50% to 20%.</p>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">After a lot of work studying where
time was being spent in HDG4, Richard has improved
performance to the point where HDG4 is now a factor of 4
slower, per event per thread, than HDG3. Very roughly
speaking, a factor of 2 comes from lower energy thresholds
for tracking and the other factor of 2 is just code speed,
i. e., the object-oriented C++ code takes twice as long to
do the same thing as FORTRAN.</p>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">We could increase the throughput by
raising thresholds, but at most that would give is a
factor of two, with possible reduction in the fidelity of
the simulation. He recommends that we proceed with the
standard thresholds, at least to start, given the
uncertainty in costs vs. benefits from ignoring physics at
low energies.</p>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">Richard is interested in receiving
problem reports as<span class="Apple-converted-space"> </span><a
rel="nofollow" class="external text"
href="https://github.com/rjones30/HDGeant4/issues"
style="color: inherit !important; background:
transparent; padding: 0px !important; text-decoration:
inherit !important;">issues on GitHub</a>. He explained
his taxonomy of such reports, listed in order of
Richard-will-look-at-it priority.</p>
<ol>
<li><b>Bugs</b>. Things that are obvious problems, e. g.
seg faults, things that halt progress, things that are
non-physical.</li>
<li><b>Artifacts</b>. Observation of behavior that "does
not make sense". These could be bugs, but they also
might be features.</li>
<li><b>Anomalies</b>. Reports of behavior of HDG4 that is
not exactly the same as with HDG3.</li>
</ol>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">Richard requires problem reports that
include a recipe for reproducing the problem. He has
provided a tool, hddm-root, that will make spectra from
the raw HDDM output of HDG4 (and HDG3). Spectra produced
in this way get around the problem of having identical
collections of versions of the software stack. In
addition, discussion on the gluex-software email list can
be used to refine improve the utility of the report.</p>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">The DIRC simulation will include
optical photons. Work here is not done but is not the top
priority at this time.</p>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">For details, see<span
class="Apple-converted-space"> </span><a rel="nofollow"
class="external text"
href="https://bluejeans.com/s/LIDGf/" style="color:
inherit !important; background: transparent; padding:
0px !important; text-decoration: inherit !important;">the
recording</a>. Richard's presentation starts at the
36:00 mark.</p>
<h3 style="break-after: avoid; font-weight: bold;"><span
class="mw-headline" id="Launches">Launches</span></h3>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">Paul have the report. Since the last
meeting Alex Austregesilo announced completion of<span
class="Apple-converted-space"> </span><a rel="nofollow"
class="external text"
href="https://mailman.jlab.org/pipermail/halld-offline/2017-January/002602.html"
style="color: inherit !important; background:
transparent; padding: 0px !important; text-decoration:
inherit !important;">Monitoring Launch, 2016-10, ver03</a><span
class="Apple-converted-space"> </span>and<span
class="Apple-converted-space"> </span><a rel="nofollow"
class="external text"
href="https://mailman.jlab.org/pipermail/halld-offline/2017-January/002603.html"
style="color: inherit !important; background:
transparent; padding: 0px !important; text-decoration:
inherit !important;">Analysis Launch, 2016-02, ver05</a>.
The analysis launch took a long time due to a small number
of events in multi-photon channels that took forever to
analyze. In these channels the cut on the number of
neutral particles had to be tightened from 20 to 14.</p>
<h3 style="break-after: avoid; font-weight: bold;"><span
class="mw-headline" id="Calibration_Efficiency">Calibration
Efficiency</span></h3>
<p style="widows: 3; orphans: 3; margin: 1em 0px;
line-height: 1.2em;">Beni has noticed that for the Fall
2016 data, more events are needed to get good timing
calibrations for the TOF. We discussed several possible
reasons for this but did not come to a conclusion about
the cause.</p>
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