Very quick ATLAS software tutorial Iacopo Vivarelli (not an expert, just a user) INFN Pisa What you find here: - How to use CMT and run Athena - How to use ATLFAST - Useful (at least, I hope) informations about instructions, HowTo, tutorials Conventions: red – commands for the prompt blue – hyperlinks violet – The OS answer

Athena - where? ● If one has an account on lxplus, that is the right place to start ● Athena kit can be downloaded and installed anywhere. Only executables and libraries are there, but the sources can be checked out from a repository (e.g. CERN) ● Many and many useful information are on the ATLAS computing page and in the ATLAS WiKi page ● For the computing: ● For the Wiki: ● Most of the informations you might need are there

ATLFAST ● In the following I will explain how to generate events and use ATLFAST (fast parametrized response of the detector) ● I won't go through the Full ATLAS simulation and reconstruction, I will give just references about it ● The final strategy in ATLAS will be to make analysis inside Athena on Analysis Object Data (AOD) (and Event Summary Data, ESD). ● Instead, I will show how to produce a ROOT (or PAW) ntuple. Refer to the computing page to know more about AODs and the Analysis Tools for them. ● ATLFAST is a particle level simulation. It is extremely useful if one wants to generate quickly a huge number of events (it takes about 1-2 hours to generate (PYTHIA) and simulate/reconstruct 100 K tt events on my Pentium Ghz single processor machine). One can easily (and quickly) get millions of events. ● It is not accurate: the response of tracker, calorimeters, muon spectrometer is only parametrized (from the full simulation). An analysis is robust if its key points are “certified” with the full simulation

How to run ATLFAST ● Everything I will say refers to lxplus at CERN. Minor changes needed if you want to run on your Athena at home. ● Good reference (actually this is for interactive athena. I won't talk about this. Anyway, most of the commands and the jobOptions are the same) ● I will go step by step

Setting up a main CMT directory (more informations)CMTmore informations ● Create an empty directory (e.g. main_cmt) ● Go into it and edit a file named requirements. It should be as follow # Set the site where you are working. For CERN set: set CMTSITE CERN # For portables: #set CMTSITE EXTSITE # Other possible values are: LBNL, BNL # Set the base location of all release for your site: macro ATLAS_DIST_AREA "/afs/cern.ch/atlas/software/dist" # Set release number, here it is (which is a good release for atlfast) macro ATLAS_RELEASE "9.0.4" // The ATLAS version you want to use, is fine for Atlfast # the AtlasSettings package centralizes the setting of basic # environment variables use AtlasSettings v* $(ATLAS_DIST_AREA) # Set the location of your prefered development area, where packages # will be checked out, (change "${HOME}/MyTest" to be any directory # path or soft link under your home directory): macro devarea "${HOME}/MyTest“ // This is the place where you are going to use packages # Add dev area to the front of your CMTPATH (but first remove any # previously defined devarea which is under your home directory) macro home_dir "${HOME}/scratch0/AtlasWork/Athena9.0.4" path_remove CMTPATH "${home_dir}" path_prepend CMTPATH "$(devarea)"

Setting up the CMT ● Check here which version of CMT you have to use.here ● Then, for it is v1r16p ● From the main_cmt directory type: source /afs/cern.ch/sw/contrib/CMT/v1r16p /mgr/setup.sh cmt config source setup.sh -tag=opt // This any time you login and you want to use Athena ● The CMT should be set. To check, verify that the enviroment variable CMTPATH has your installation directory (MyTest in the previous slide) as the first directory and that CMTROOT is defined to the right CMT version ● The -tag=opt option means that you don't want to run the debugger on the compiled packages (see later). Leave it there if you want only to use Athena, remove it if you plan to develop software This only the first time

Checking out packages ● Now you have to check out a package ● The software tree can be browsed herehere ● Use RecExCommon: fine for ATLFAST and ready for the full reconstruction ● Check which is the tag of the wanted package in the release you want ls /afs/cern.ch/atlas/software/dist/9.0.4/Reconstruction/RecExample/RecExCommon/ RecExCommon ● Then we want the tag of RecExCommon ● Go into the MyTest directory ● Then, check it out cmt co -r RecExCommon Reconstruction/RecExample/RecExCommon ● This produces a Reconstruction/RecExample/RecExCommon/RecExCommon directory in your MyTest. Go there.

Set up and compile packages ● There are some important directories here: cmt – directory to set up CMT of the package, to compile.... share - the jobOptions (see later) of the package are here doc – some scripts and maybe documentation ● If instead of RecExCommon one checks out another package cmt co -r JetRec Reconstruction/JetRec then there are two more directories JetRec (the headers directory) src (the sources directory) ● Go into the cmt directory. Then cmt config source setup.sh // This also has to be done each time you login gmake

Almost done..... ● If no error messages appear, then Athena should be ready to run. One can check that athena.py is in the $PATH which athena.py /afs/cern.ch/atlas/software/dist/9.0.4/InstallArea/share/bin/athena.py ● You are in the cmt directory: go into the../run directory and type RecExCommon_links.sh. This produces a number of files in the run directory ● Be sure that the file PDGTABLE.MeV is there ● To summarize, after the setting up of everything, each time you login you have to do the following In the main_cmt directory: source setup.sh -tag=opt In the MyTest directory: cd Reconstruction/RecExample/RecExCommon/RecExCommon- /cmt source setup.sh

Setting up a jobOption ● In the following I assume to run Pythia (with the default settings) and to use ATLFAST on the events produced. ● A jobOption is an input file for Athena. The jobOptions specifies what you are going to do. ● It uses python ● You can use the following skeleton (let's name it my_atl_job.py)

# This job options file runs Atlfast in the Athena framework theApp.setup( MONTECARLO ) // The App is the main application of Athena include( "PartPropSvc/PartPropSvc.py" ) #* load relevant libraries // The following commands load the libraries for Pythia, Atlfast, Gaudi (the core of Athena) theApp.Dlls += [ "Pythia_i"] theApp.Dlls += [ "GaudiAlg"] theApp.Dlls += [ "AtlfastAlgs"] theApp.Dlls += [ "RootHistCnv" ] theApp.ExtSvc += ["AtRndmGenSvc"] # # Persistency services # # you should not need to change this EventPersistencySvc.CnvServices = [ "McCnvSvc" ]; # Setting the Pythia seeds AtRndmGenSvc = Service( "AtRndmGenSvc" ) AtRndmGenSvc.Seeds = [ "PYTHIA_INIT ", "PYTHIA " ] //random seeds # This is the name of the file where your histograms will be created. # theApp.HistogramPersistency="ROOT" HistogramPersistencySvc = Service( "HistogramPersistencySvc" ) HistogramPersistencySvc.OutputFile = "ArtemisAtlfastJob.rz" NtupleSvc = Service( "NtupleSvc" ) NtupleSvc.Output = ["FILE1 DATAFILE='ttH.root' TYP='ROOT' OPT='NEW'"] # # Event related parameters # # Number of events to be processed (default is 10) theApp.EvtMax = // maximum number of events

# # Private Application Configuration options # # OUTPUT PRINTOUT LEVEL # Set output level threshold (2=DEBUG, 3=INFO, 4=WARNING, 5=ERROR, 6=FATAL ) # you can override this for individual modules if necessary MessageSvc.OutputLevel = 5 # Execution of algorithms given in sequencer # theApp.TopAlg = ["Sequencer/TopSequence"] // the main application is a sequence of algorithm TopSequence = Algorithm( "TopSequence" ) TopSequence.Members = ["Sequencer/Generator","Sequencer/Atlfast"] // The algorithms that belong to the sequence # #GENERATORS SETUP (select by uncommenting/commenting) # #Generator.Members = {"Isajet"}; Generator = Algorithm( "Generator" ) Generator.Members = ["Pythia"] # uncomment this option if you want top # contribution to cross sections Pythia = Service( "Pythia" ) include( "ttH.inc" ) // all the settings of Pythia are here, see the next slide include( "AtlfastAlgs/AtlfastStandardOptions.py" ) // All the Atlfast settings are here Have a look at the ATLFAST webpage for more informationsATLFAST webpage

Pythia.PythiaCommand = [ "pyinit pylisti 12",\ "pysubs msel 0",\ "pysubs msub 121 1",\ "pysubs msub 122 1",\ "pypars mstp 82 4",\ "pydat1 mstj 22 2",\ "pydat1 mstj 11 3",\ "pydat1 parj ",\ "pydat1 parj ",\ "pypars parp ",\ "pypars mstp 128 0"] This is the content of the ttH.inc file. Of course it can be put directly into the jobOptions The syntax is: - name of the pythia routine - name of the pythia variable (vector) - number of the component - value Let's have a look at the Atlfast Options. We need the AtlfastAlgs/AtlfastStandardOptions.py file To get a jobOption from the distributions, one can use the get_joboptions command: get_joboptions AtlfastStandardOptions.py

The first lines set some algorithms that can be executed #Atlfast.members +={"Atlfast::TrackMaker/TrackMaker"}; Atlfast = Algorithm( "Atlfast" ) Atlfast.members +=["Atlfast::Monitor/Monitor"] #Atlfast.members +={"Atlfast::TrackNtupleMaker/TrackNtupleMaker"}; # Atlfast.members +={"Atlfast::StandardNtupleMaker/StandardNtupleMaker"}; //uncomment this # Atlfast.members +={"Atlfast::ExampleAnalysis/ExampleAnalysis"}; # Atlfast.members +={"Atlfast::AtlfastProtoJetMaker/AtlfastProtoJetMaker"}; If one uncomment the marked line (and change the syntax to python), one will get the standalone atlfast ntuple. Then, one changes the last line of the jobOption. Change include( "AtlfastAlgs/AtlfastStandardOptions.py" ) into include( "AtlfastStandardOptions.py" ) to use your local AtlfastStandardOptions.py

Then run. This should produce an root ntuple: athena.py my_atl_job.py If you don't get error messages and at the end you have a file called ttH.root in your directory, then the first job has been run. Into AtlfastStandardOptions.py there are most of the parameters for the ATLFAST simulation/reconstruction The minimum P T for electrons, photons, isolated and non-isolated muons, reconstruction, the reconstruction cone for clusters and jets, the value for the b-tagging and tau-tagging efficiency and many other options are there. The Atlfast manual is useful to understand the meaning of the options (it is the manual for the fortran version, but there are no big differencies)Atlfast manual Something about the options can be found also on the / /

What is in the ntuple Look here to get more informations about the atlfast ntuplehere There are a number of blocks, with similar structure. PLEPTONS  Isolated electrons and muons. Available variables: nele,pxele,pyele,pzele,eeele,kfele (the pdg code of the reconstructed electron); the same for muons. PPHOTONS  Isolated photons. Available variables: the same PMUXS  Non-isolated muons. Available variables: the same PPJETS  Jets and AtlfastB jets. Available variables: the same for jets plus PTcalo,PTbjet,Ptujet (PT of all the jets, of the true bjet, of the true ujet), then the same for AtlfastB jets. PHISTORY  Parton level informations PMISSING  Missing E T informations

Be careful: pxjetb IS NOT the px of b-jets. The b flag at the end of the jet variable name means that those are the variables obtained running AtlfastB. What is AtlfastB: it is a simple routine that provides b-jet and tau-jet identification according to the tagging and mistagging efficiencies set in the AtlfastStandardOptions.py files. If you use the default, the b-tagging efficiency is 50% with pt dependent mistagging for c and u jets. Then, a random number is thrown and it is compared with the tagging probability according to the true identifier (KFJET). After the jet tagging, calibration constants for the out of cone energy are applied. One should use the jetb variables (pxjetb,pyjetb etc.) if he/she is interested in reconstructed id and calibrated jets.

Some further information -Instructions for downloading and installing athena somewhere: you need a machine with rh7.3 or SLC3 installed (I don’t know what happens with different OS). It needs about 5 GB on the hard disk (maybe more for the installation). Then follow the instructions: InstallingAtlasSoftware < Atlas < TwikiInstallingAtlasSoftware < Atlas < Twiki - Running Herwing / How to interface external events (generated with Alpgen, AcerMC, CompHep, etc.) with pythia/ATLFAST or Herwig/ATLFAST: indexindex - Running the ATLAS reconstruction on full simulated events:Reconstruction in AthenaReconstruction in Athena -Trigger simulation (LVL1 and HLT): see Atlas UK Simulation - Level2Atlas UK Simulation - Level2 For any question you can contact me: Either I can answer or I can redirect the question……….