Hi Kris, On Thu, 21 Jun 2001 21:55:24 -0500 (CDT) Kris Hagel <hagel@cyclotronmail.tamu.edu> wrote concerning ": BRAT2": > In the meantime, I have made yet another iteration (with brat2!!!) on the > geometry database. I just had an idea for the geometry database: Why not use the Sector table in BrahmsMain as the index into what you call "PlatformPosition" - or more generally "Position". Then ofcourse, we should have the following entried in the "Sector" table: MRS FFS BFS GLB and we could define the D1 platform as a volume (or "detector") in FFS. Then we'd have a table called Volume, with the following attributes id <= Volume ID number detectorId <= From BrahmsMain::Detector or BrahmsMain::Sector motherId <= From BrahmsGeom::Volume This table just tells us which volume a given volume is in (a one-to-many relation). In this way, we'll use the same logical name for both calibrations and geometry. Then we'd have the table "Position" with attributes id <= Position id volumeId <= From BrahmsGeom::Volume position_x <= position in mother position_y <= position in mother position_z <= position in mother theta <= rotation in mother phi <= rotation in mother psi <= rotation in mother starttime <= Start of when valid endtime <= End of when valid and a table "Size" with attributes: id <= Position id volumeId <= From BrahmsGeom::Volume half_x <= Size half_y <= Size half_z <= Size starttime <= Start of when valid endtime <= End of when valid In the above table, we could replace half_[x|y|z] with a Floating point array of say dimension 12, and a string identifier that identifies the shape: id <= Position id volumeId <= From BrahmsGeom::Volume shape <= string of GEANT3.21 shape shape_params <= 12D (?) floating point array. starttime <= Start of when valid endtime <= End of when valid Note that the last option makes the database very flexible and could probably also be used to write volume defintions for BRAG. Also, the user is free to use what ever remaining paramaters in shape_params for other information, such as magnet effect-edge position and so on. I believe the above scheme is what we need and also flexible enough to be extended more in the future, and indeed general enough to hold all the information. Yours, Christian ----------------------------------------------------------- Holm Christensen Phone: (+45) 35 35 96 91 Sankt Hansgade 23, 1. th. Office: (+45) 353 25 305 DK-2200 Copenhagen N Web: www.nbi.dk/~cholm Denmark Email: cholm@nbi.dk
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