Minutes of the July 10, 2013 LBNE Sim/Reco group meeting
Tom Junk, Jonathan Insler, Eric Church, Tyler Alion, Kevin Wood, Brett Viren
Apologies to those omitted
We have been desiring our own software repository for quite a long time now.
Tyler has been working on disambiguation algorithms for some time now and would
like to share code with collaborators (such as Jae), and also not have to worry
about accidentally colliding with ArgoNeuT and MicroBooNE. At the LArSoft
stakeholders' meeting July 9, we were largely in favor of moving forwards to
using git in place of svn for the LArSoft repository. We can go ahead and
use git with our new repository to reduce migration in the future and to get
a head start on using the new system. Tyler suggests calling the new
repository lbne-fd, and Brett has created it as a subproject to lbne-software.
The granularity of what goes into a separate repository vs. packages is an
interesting question. Lynn Garren has a proposed granular breakup for the
We are considering a similar fine-graining of LBNE packages, but would like
some flexibility as we learn as we go along. Since you clone an entire repository
as the minimum checkout in git, it pays to have small repositories, while packages
that are not being worked on can be gotten out of ups. We need setup and build scripts,
as well as a way for Redmine to show checkin history and documentation. It may be easy
to write a script to update the DOxygen content from all the repositories within a
Redmine project so that searching for keywords is easier.
Tyler ran into an issue with fuzzyclustering's centroid finder.
The distance formula wraps easily, finding an average position to compute a
cluster centroid doesn't map well onto a wrapped space. Tyler proposes mapping
the channel number in an induction plane to a unit circle, and then doing a charge-weighted
average of the x and y positions in this space to get the centroid. Tom is concerned about
events that wrap all the way around this circle like throughgoing cosmics.
Tyler is talking with Jae about making an analysis module that characterizes the performance
of the disambiguation. On the list of things to put in it are the fractions of correctly
disambiguated induction hits, where the denominator is all induction hits. Another is to
see how the tracking is affected by comparing the MC track ID with reconstructed track ID's to see
if disambiguation is contributing to splitting or merging tracks.
We plan on having a meeting on Friday for Jae's disambiguation presentation.
Tyler would like samples of GENIE + CRY events for 10 kT on the surface. Eric says that
MicroBooNE did a multi-step simulation -- GENIE and CRY were run in subsequent jobs, each
adding their output to the ART-formatted rootfile. A third job ran the simulation, where
LArG4 knew to read in all the particles made with GENIE and CRY. Tyler says that it is easy
to get correct disambiguation rates exceeding 90-95% with single particles, and wants to try
a harder problem. Eric sent around a link to a fcl file from MicroBooNE that does this.
Jonathan is working on a fast hit-finder that runs on raw digits instead of deconvoluted
recob::Wire data, as we will be needing that for a 35T online trigger. It runs, but finds
fewer hits than the GausHitFinder. Tom suspects that GausHitFinder is better at pulling apart
multiple hits that are bunched up together, and that for triggering purposes for 35T, this
it may not be that necessary to get them all. But we do want basic timing resolution for the
hits and to make sure that hits aren't simply lost. Calwire is there to unpack the raw digits
and to get the pedestal from the input data products.
Tyler would prefer that the combined unpack/deconvolute/hit-finder module Jonathan has been
working on moves forwards so that we can start reconstructing 10 kT MC. As it is, it is quite
slow and takes a lot of memory (8 Gb). Even if it is slow, if we can get it under 2 Gb we
can run the job on Fermigrid. Jonathan is putting that module together and is working on
the time-domain deconvolution part.
There are minutes attached to this event.