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NS: Think I solved these problems. Didn't put in the CVS.
JS: Test cases. Tried to get point along trajectory with negative distance. But doesn't work with POCA. DOCA works, point -> trajectory. POCA along trajectory does not work.
MC: Trajectory needs a few more accessors. What is the direction on a given point of the trajectory?
NS: In the helix, there is getMomentum() at a point, which is direction. Just need access to the helix itself. Useful to have getTrajectory() from the swimmer.
MC: Committed a bunch of accessors for the line but marked as deprecated, because should go into main interface.
NS: Distance is always positive.
TJ: Always make origin of POCA at (0,0,0)?
TJ: Take closest point in particular direction.
RP: Would like to second NS's request for more functionality. Right now, can initialize a swimmer with a track but not track parameters.
Methods for getting not just first intersection but arbitrary intersections (2nd, 3rd, 4th, etc.). Specific track parameters as single object and get intersections.
TJ: NS suggesting something different. Always give the cylinder intersections from (0,0,0) point.
MC: Could imagine where wouldn't want to start near (0,0,0).
RP: First POCA along trajectory where there are hits. May or may not be close to (0,0,0). Find some hits -> make track. Should be DOCA defined by the seed.
NS: Can get all other points easily if agree to have POCA as origin of the track. Method findPointAtLength(). Increase length by one rotation and will find all other points.
RP: No doubt that it can be done in the code. Encapsulate the facilities in main interface.
TJ: Noticed in MC's code, used ParallelLineException, but should use NaN, instead.
NG: Any more updates from RP?
RP: Discussion last week about what classes should come out of track digitization. Good suggestions from NS. Assume we're going forward with this? Someone needs to figure out raw hit format, persistence.
TJ: Trying to make compatible with LCIO. Can't arbitrarily change time to ID. Somewhat constrained by compatability with LCIO. Can change or "cheat".
NS: Waiting for TJ to define the TrackerHit interface. Right now, make TrackerHit implementation. Waiting for the final definition of what is a TrackerHit, e.g. Hep3Vector or array.
NG: Updates from JS?
JS: Trying to understand the helix problem, write tests to fix problem reported by NS. Might need help understanding the HelixSwimmer.
Still need a way to quantify the ZvTop performance, e.g. real position vs. found position, precision.
NG: org.lcsim forum has been added at linearcollider forum.