Review of the

1
Review of the Core softwareIntroduction

• Environment THB, Thomas, Ian, Heather
• Geometry Joanne
• Monte Carlo THB, Masanobu
• Reconstruction Ian
• Planning THB

2
Coding technology choices

• Platforms Win NT/2000, linux, solaris
• Language Object-oriented C, w/ coding rules
• Documentation Doxygen
• Repository CVS at SLAC, remote access via ssh.
• Organization/build tool CMT
• Framework GAUDI

3
CMT

• Inspired by bad experience with SRT (sorry,
  BaBar)
• Executable that creates build instructions
  (makefiles, DevStudio files) for products, like
  executable programs.
• Defines a basic unit of software, the package a
  package can have multiple versions, accessible
  simultaneously.
• Defines use relation ships among packages/version
  combinations
• Supported by Orsay, used by many experiments
• documentation, web site
• mail list
• Independent of CVS, but maps well, has explicit
  support
• CMT version ? CVS revision

4
CMT disk structure
5
Package model
6
The GAUDI Framework

• A framework that defines an architectural style
  for event-oriented analysis
• Used by four other experiments, excellent
  support, documentation
• Implication software components, containing
  classes that implement abstract interfaces of
  specific types
• Service (many exist already, easy to add new ones
  )
• DataObject (Transient Data Store Ians talk)
• Algorithm (where use code goes Ians 2nd talk)
• Converter (Heathers talk)
• Summary
• A CMT package may define a Gaudi component and a
  test program
• The component may implement one or more
  DataObjects, Algorithms, etc.

7
Coding environment for developers

• Traditional
• insert debug printout statements
• compile, link, execute
• study output
• go back to step 1
• More efficient alternative
• GUI interface with 3-D graphics
• Debugger
• 3-D graphics available Two new packages
• GuiSvc, a Service which transforms Gaudi app to
  use windowing env. and makes the gui operations
  available
• IrfDisplay initial example of an Algorithm that
  displays hits from glastsim.
• Future probably integrate with, and adopt the
  HepRep/WIRED sheme
• Joe Perls talk tomorrow

8
A look back to 21 June 1999
9
Now

• It is GlastSim, WBS 4.1.D.2

10
Simulation in five easy pieces

1. Source description, including spectrum, rate,
   angular dependence, geomagnetic latitude, orbit
   orientation, GLAST inclination 
2. External geometry description
3. Concrete rendering of the detector for the
   simulation package 
4. Generation of hits (and thus a definition of the
   hit classes.)
5. Conversion of hits to digis for analysis

11
Traudls picture
1
4
3
2
5
12
Simulatation status, plans

• Old glastsim converted to packages, still in use.
  Output available as Gaudi event service. Start of
  display.
• Geometry interface (Joannes talk) not critical
  path for balloon
• Simulation as a Gaudi service
• Geant4 LHCb has done it?
• Gismo on TO-DO list for THB
• Hit classes for interface to digi code see
  Masanobus talk.

13
To-dos

• Framework
• Need procedures (reviews?) to give meaning to
  coding rules
• Definition of releases
• Validation of critical code
• Enable display of detector, tracks, recon objects
• Monte Carlo
• Instantiate geometry
• Define Gaudi service
• Create hits
• hits ? digis
• Reconstruction