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minutes of meeting 2004-04-13 [message #72 is a reply to message #30] Thu, 15 April 2004 17:49 Go to previous messageGo to previous message
Messages: 80
Registered: January 2004
9:11 AM 4/13/2004


NG: QA on lelaps LCIO output ongoing, Will aim to put into cvs
this week. Plan to run same events through lelaps and lcs
for independent check of lcio output.

FG: Implementation of simulator status bit not done.
working on Reco data model. Modifications agreed to in last meeting
included removing data namespace and java package data.
cleans up API.
TJ: still has some concerns about doing this.
Reason to have data namespace is to be able to use existing classes.
in existing lcd reco, we generate different instances of clusters,
e.g. don't have to tie the data to the data format as long as one has
an adapter. New model would insist that reco directly creates these objects.
FG: could also implement event interface which writes lcio w/o instantiating
lcio classes.
TJ: would like to write a toy reco model to see if he can still decouple
the reco model from the persistence model.
lcio concept has changed over time. would still like to see if
this can be made to work.
FG: introduced pointers to hits. last week used indices, which noone liked
so implemented to use real pointers, adds some to the file overhead,
but seems reasonable.
will also need to point between simtrackerhits and raw tpc hits, so
it makes sense to introduce these pointers.
in current implementation, for raw tpc and cal hits, made the pointer
optional. if only writing out raw data, don't need these pointers.
once these are used, and pointed at, the size will grow. now much more
updated the posting in the forum.

FG: generic tracker hits proposed.
NG: concerned that this is OK for 3D hits, or 2D on a surface, but not
so good for 1D measurements. Important point is that what we need now
is something to get started, i.e. recognize the need for such a generic
*NG needs to write up specific objections to the proposed trackerhit
and propose what that interface should be.
FG: discussion of overall model at:

*important to stress at LCWS to point to a design and even a BETA implementation.
All agreed that overall design is OK

FG: heplorentzvector issues:
1.) not a good idea to inherit from clhep's lorentzvector
has ~80 methods!
no control over access of data, can't impose read-only access
heplorentz methods, e.g. boosting, changes internal data
if ReconstructedParticle inherits from heplorentz vector, then RP data
gets modified.
2.) implemented something which is a class which copies data to the 4vector
which can be used in 4vector calculations, but retains data.
implemented in C++ for MCParticle, and would need only a few lines
of code for RP.
3.) do we want to proceed along these lines?
consensus is to adopt this as a working hypothesis and see how far we

NG: Would one iterate over the RP collection and then get 4Vector for each
to feed, e.g. to a jetfinder?
TJ: RP collection could have method such as returnAsHepLorentzvector()
to get a collection of 4vectors.
FG: thinking about object handlers and utility classes, but not yet needed.

3.) release plan:
ETA for java beta release of reconstruction objects.
TJ: before end of month.
1st stage is simply implementation of our current static model
2nd stage would be to implement a toy reconstruction program which
exercises this.
* important thing for Paris is to present the model, and thoughts for
the implementation. Stress that implementation is beta, and subject to change.
FG: started with Java implementation for RP. using Eclipse as IDE.
check in to cvs, we will look at it here.

TB: still experiencing lack of email notification when subscribed
to forum.
TJ: found bug in the emailing code. has fixed and patched local version.
will upgrade when fixed by author.

prototype forum setup, ready for users.

Meet again May 3, after LCWS and after ITRP visit to SLAC.
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