Include a new Algorithm

Athena setup

Setup the athena enviroment with asetup. This one works for me.
Add the following lines to your ~/.bash_profile:

export AtlasSetup=/afs/cern.ch/atlas/software/dist/AtlasSetup
alias asetup='source $AtlasSetup/scripts/asetup.sh'

(this has to be done only once of course). Then issue

asetup 16.0.2.5 

to setup in AtlasProduction 16.0.2.5.
Make a directory

mkdir $TestArea

and cd there. Then check out the package Trigger/TrigAnalysis/TrigAnalysisExapmples. For this, first check, which version corresponds to your release. Do

cmt show versions Trigger/TrigAnalysis/TrigAnalysisExapmples

Strange enough this shows a really old package (TrigAnalysisExamples-00-00-22), so I checked out the newest version anyway. (Normally you would check out the one shown by cmt show versions.) Anyway, the newest version worked for me. I checked it out by doing

cmt co -r TrigAnalysisExamples-00-00-27 Trigger/TrigAnalysis/TrigAnalysisExamples

To make sure you haven't screwed up anywhere, you might want to compile and run:

cd $TestArea/Trigger/TrigAnalysis/TrigAnalysisExamples/cmt
make -j5
mkdir $TestArea/run                                 # to create a run directory
cd $TestArea/run
get_files TrigMatchExampleJO.py                     # to grab the joboptions file
athena TrigMatchExampleJO.py | tee joblog           # | tee joblog = shows output on screen and also writes it into joblog

If every thing's fine, you can add a new algorithm.

Add a new algorithm

To add your own TriggerAnalysis algorithm from scratch, do the following. In Trigger/TrigAnalysis/TrigAnalysisExapmples/src create a file TriggerAnalysis.cxx and its header, TriggerAnalysis.h (note that in most other packages, the header files are stored in TrigAnalysisExapmples/TrigAnalysisExapmples. Your algorithm should be able to do the following

• retrieve the reconstructed and the trigger objects
• make some trigger studies
• save everything to a ntuple

In order to create a nice ntuple (which would even be re-readable by athena), you should inherit from CBNT_AthenaAwareBase. Alternatively, you can inherit from AthAlgorithm.