Tracks in the data structure

From: Stan Seibert (volsung@physics.utexas.edu)
Date: Thu Dec 01 2005 - 14:33:35 CST


Another item from the meeting:

I have code now which gathers track information during the GEANT4
simulation and puts it into the data structure. It's not as detailed
as I like (some optical photon interactions are not correctly
tagged), but it is much better than no information, like we have
currently. I'm finishing up with some helper classes that will allow
ROOT macros to load a track list from disk and build a data structure
in memory that is actually useful for answering physics questions.
(Who is my parent? Which daughters were produced? Go to the track
start. Etc, etc.)

Josh said it might be worthwhile to break the "freeze" and add the
track feature to the code for the 0.1 release. Are there any strong
opinions either way? It should not be a major issue since it does
not affect anyone's current macros. Collection of track information
is by default off. However, if someone adds

/tracking/storeTrajectory 1

to their macro, then GEANT will collect tracks, and Gsim will
automatically put them into the data structure. So, unlike most of
my recent changes, it is backward compatible and there should
hopefully be few surprises. (Prepare for large files if you turn
this on. Each IBD event is something like 8 MB on my test machine
with all 40000 tracks. Clearly we will need to extend the pruner
with a "cut optical photon" option.)

So, what are people's views on this? Bump it to version 0.2 or delay
0.1?

---
Stan Seibert


This archive was generated by hypermail 2.1.6 : Fri Dec 02 2005 - 00:01:02 CST