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- There are two cluster options on the table. A class like Rob's or Rich's stripped down version. Something like Dima suggested. We have not yet made a decsion on this.
- We will add some organized container of clusters to the event. Perhaps along the model Rob suggested, perhaps a different one. If we go with 1b), the container will hold ClusterData.
- If we go with 1b), should we also add a parallel container of TrackCluster objects instantiated with a null helix?
- There are no plans to persist clusters.
- We do not have a solution to bookkeeping which hits remain available for subsequent pattern recognition. What ever solution we choose, it will not modify clusters that are already in the event.
Track Fitters
There are a several track fitters in various states of readiness:
- Norman's TRF. Still needs code to load its geometry from the org.lcsim geometry and code to load its hits from org.lcsim clusters.
- Nick's, weight matrix fitter
- Caroline's Kalman filter used for muon tracking and could be extended for vertex+tracker.
- Kfitter+SOD Tracker - there is a kalman filter in there but I don't know exactly where.
- We do not have proper output classes for any of these.
TrackerHits
- We plan to persist TrackerHits. However they have ceased being useful objects for anything except graphics. They are now the product of pattern recognition and track fitting, not their input as originally envisioned.
- If we modify TrackerHit to point to cluster information and if we do no persist the clusters it is not possible to run one job to create TrackerHits and later run many jobs to test pattern recognition code.
- We plan to shoehorn clusters into TrackerHits? We plan to shoehorm TRF hits into TrackerHits. Is this self consistent? Maybe, if we add a type field to TrackerHit - which we probably need to do anyway.
Cheaters
A variety of pattern recognition cheaters exist. So far as I know they only work in the barrel and only work for the cylindrical tracker geometry.
Configuration and Metadata
- We have no mechanism for run time configuration. At many points in the discussion we noted that we need one.
- LCIO allows metadata to be associated with each object stored in the event header. We can and should make use of this to describe how the objects were made: versions of code, run time configuration information.
Old Style Geometries
There are many existing lcio files containing events simulated with the cylindrical vertex and tracking detectors. It will still be possible to read these files and instantiate the geometry representation. Old code will continue to work. Pattern recognition code developed for the planar detectors is unlikely to work with this old files.