I'm trying to organize positron track data from E821 at BNL and have a
question concerning the use of trees. The data is naturally divided
into the hiarchial levels: run number, record number, fill number,
straws hit, and finally tracks. My question is, how do I organize a
tree such that the data is divided into the following?
ROOT
/\
/ \
run 1 run 2 ....
/\
/ \
rec 1 rec 2 ...
/\
/ \
fill 1 fill 2 ....
/\
/ \
track 1 track 2 ....
/\
/ \
(raw) data1 data2 ..
To I want to make several trees and enter them into the branches? For
example, the first tree comprises the ROOT, the branches of the root
contain several trees for each record, whose branches contain trees for
fills, etc. etc. etc... , all the way to the data which is contained in
branches themselves? Or should the raw data be kept in a TClonesArray,
but everything else is fine? What is the best way to approach this
organization, and how is it booked? Is it booked from Root down, or from
data up?
William J. Deninger
deninger@uiuc.edu