XAOD Tutorial

8/20/2019 XAOD Tutorial

1/22

xAOD Tutorial

12/11/2014 J.Kirk, UK-HLT Mini workshop, Sussex 1

Aims:

Browse an xAOD with ROOT Interactive Root & PyRoot with xAOD

Analysis using ROOT

Analysis in athena & TrigDecisionTool


2/22


Disclaimer

I am NOT an expert. Just trying to give a flavour of what is possible.

Usual ATLAS software tutorial is a week and xAOD mini-tutorial is 2 days.Most recent ones:

https://indico.cern.ch/event/329880/other-view?view=standard

https://indico.cern.ch/event/330324/other-view?view=standard

Useful Links:

https://twiki.cern.ch/twiki/bin/viewauth/AtlasComputing/SoftwareTutorialxAODEDM

https://twiki.cern.ch/twiki/bin/viewauth/AtlasComputing/SoftwareTutorialxAODAnalysisInROOT

https://twiki.cern.ch/twiki/bin/view/AtlasComputing/SoftwareTutorialxAODAnalysisInAthena

https://indico.cern.ch/event/329880/other-view?view=standardhttps://indico.cern.ch/event/330324/other-view?view=standardhttps://twiki.cern.ch/twiki/bin/viewauth/AtlasComputing/SoftwareTutorialxAODEDMhttps://twiki.cern.ch/twiki/bin/viewauth/AtlasComputing/SoftwareTutorialxAODAnalysisInROOThttps://twiki.cern.ch/twiki/bin/view/AtlasComputing/SoftwareTutorialxAODAnalysisInAthenahttps://twiki.cern.ch/twiki/bin/view/AtlasComputing/SoftwareTutorialxAODAnalysisInAthenahttps://twiki.cern.ch/twiki/bin/viewauth/AtlasComputing/SoftwareTutorialxAODAnalysisInROOThttps://twiki.cern.ch/twiki/bin/viewauth/AtlasComputing/SoftwareTutorialxAODEDMhttps://indico.cern.ch/event/330324/other-view?view=standardhttps://indico.cern.ch/event/330324/other-view?view=standardhttps://indico.cern.ch/event/330324/other-view?view=standardhttps://indico.cern.ch/event/330324/other-view?view=standardhttps://indico.cern.ch/event/329880/other-view?view=standardhttps://indico.cern.ch/event/329880/other-view?view=standardhttps://indico.cern.ch/event/329880/other-view?view=standardhttps://indico.cern.ch/event/329880/other-view?view=standard


3/22

Setup


setupATLAS

mkdir xAODTutorial

cd xAODTutorial

rcSetup Base,2.0.10

export ALRB_TutorialData=/afs/cern.ch/atlas/project/PAT/tutorial/cern-oct2014/

Standard atlas setup – gives access to softw

Setup the release we want to use

Pointer to some data


4/22

Browse an xAOD with ROOT


root

$ALRB_TutorialData/r5591/mc14_8TeV.117050.PowhegPythia_P2011C_ttbar.recon.AOD.e1727_s1933_s1911_r5

591_tid01494882_00/AOD.01494882._113691.pool.root.1

root[0] TBrowser b;

The TTree containing the variables is called CollectionTree.

You can look through and “double-click” to see some of the variables.

Have split the interface to objects and how the payload is stored (“aux” containers). In code user interacts with

the interface NOT with the auxilliary storage.

For fun we can look at a run1 AOD:

root root[0] TFile *f =

TFile::Open("$ALRB_TutorialData/mc12_14TeV.105200.McAtNloJimmy_CT10_ttbar_LeptonFilter.recon.AOD.e15

65_s1499_s1504_r4033_tid01014997_00/AOD.01014997._000081.pool.root.2");

This is already a very good thing about xAOD.


5/22

Interactive ROOT with the xAOD


root [0] gROOT->Macro( "$ROOTCOREDIR/scripts/load_packages.C" );

root [1] xAOD::Init();

root [2] f = TFile::Open(

"$ALRB_TutorialData/r5591/mc14_8TeV.117050.PowhegPythia_P2011C_ttbar.recon.AOD.e1727_s1933_s191

1_r5591_tid01494882_00/AOD.01494882._113691.pool.root.1", "READ" );

root [3] t = xAOD::MakeTransientTree( f )

root [4] t->Draw( "ElectronCollection.pt() - ElectronCollection.trackParticle().pt()" );root [5] t->Draw( "Muons.pt()");

Once you have done “MakeTransientTree” can now click things in TBrowser by using root/Root

Memory/CollectionTree


6/22

PyROOT with the xAOD


PyROOT is very handy when you want to run a quick macro

cp /afs/cern.ch/work/h/hartj/public/xAODTutorial/xAODPythonMacro.py .

(chmod +x xAODPythonMacro.py)

./xAODPythonMacro.py

Should print some output about electrons and muons to the screen


7/22

Analysis using ROOT


Create a new Analysis package:

rc make_skeleton MyAnalysis

rc find_packages

rc compile

We will use the standard “EventLoop” package for looping over events.

The EventLoop package provides a script to create the skeleton of the class for you inside the

package you specify

$ROOTCOREBIN/user_scripts/EventLoop/make_skeleton MyAnalysis MyxAODAnalysis

rc find_packagesrc compile

These 3 lines create a new package

and then asks RootCore to pick it up.


8/22

Accessing the xAOD quantities from our analysis code


In MyAnalysis/cmt/Makefile.RootCore add

PACKAGE_DEP = EventLoop xAODRootAccess

at top of MyAnalysis/MyAnalysis/MyxAODAnalysis.h add:

// Infrastructure include(s):

#include "xAODRootAccess/Init.h"

#include "xAODRootAccess/TEvent.h"

Add as public:

xAOD::TEvent *m_event; //!

“//!” is important!!!!!

Update the package dependencies,

EventLoop should already be there

To do any sort of real analysis you will access the xAOD objects using a package called xAODRootAccess. The most important class is the xAOD::TEvent class, which acts similar to the D3PDReader.

We will also use the xAOD::Init class to handle any xAOD access magic that will happen behind the scenes to the

user.

Add header files and a new data member

https://svnweb.cern.ch/trac/atlasoff/browser/Control/xAODRootAccesshttps://svnweb.cern.ch/trac/atlasoff/browser/Control/xAODRootAccess


9/22

Accessing the xAOD quantities from our analysis code (2)


In MyAnalysis/Root/MyxAODAnalysis.ccx

In setupJob() add:

job.useXAOD ();

// let's initialize the algorithm to use the xAODRootAccess package

xAOD::Init(

"MyxAODAnalysis" ).ignore();

// call before opening first file

In initialize() add:

m_event = wk()->xaodEvent();

// as a check, let's see the number of events in our xAOD

Info("initialize()", "Number of events = %lli", m_event->getEntries() ); // print long long int

Now remake the package:

rc find_packages

rc compile

Tell EventLoop that we actually want to use the

xAODRootAccess in our job.

Ignore return code (failure, success, and

recoverable)

Connect this member to out xAODRootAccess.

updated our package dependencies, so from our

working directory we have to rerun rc find_packages

before compiling:


10/22

Running our algorithm


mkdir run

cd run

cp /afs/cern.ch/work/h/hartj/public/xAODTutorial/ATestRun.cxx .

This uses a standard tool SampleHandler to manage sample management.To execute it:

root -l 'ATestRun.cxx ("submitDir")'

submitDir is the directory where the output of

your job is stored. If you want to run again, you

either have to remove that directory or pass a

different name into ATestRun.cxx.


11/22

Running our algorithm - alternative


In order to debug problems with the code, it is often not practical to run the job from ROOT's interpreter. So,

if you encounter any problems, you should create a directory like MyAnalysis/util/, and in there put an

executable source file like MyAnalysis/util/testRun.cxx

cp /afs/cern.ch/work/h/hartj/public/xAODTutorial/testRun.cxx .

In working directory

rc compile

Then from run:

testRun submitDir


12/22

Finding out what is on the xAOD


One question everyone will have is: how do I know what information/variables are actually stored

in my xAOD for each container type?

Need to know the container type and the container key name.

We can use checkSG.py in Athena.

Setup a new lxplus session:

% setupATLAS

% asetup 19.0.3.1,slc6,gcc47,64,here

% export ALRB_TutorialData=/afs/cern.ch/atlas/project/PAT/tutorial/cern-oct2014/

% checkSG.py


591_tid01494882_00/AOD.01494882._113691.pool.root.1

You usually need to know the container type on left (for example xAOD::CaloClusterContainer) and the key

name for the particular instance of that container you are interested in which is on the right (for example

"egClusterCollection").

% checkSG.py

/afs/cern.ch/work/h/hartj/public/valid1.117050.PowhegPythia_P2011C_ttbar.recon.AOD.e2658_s1967_s1964_r

5856_tid01600225_00/AOD.01600225._000084.pool.root.1


13/22

Finding out what is on the xAOD (2)


To know what variables are associated to this container, the trick I use at the moment (again maybe something

official will come along...) is to use interactive ROOT.

root -l


591_tid01494882_00/AOD.01494882._113691.pool.root.1

root [1] CollectionTree->Print("egClusterCollection*")

You will get a printout of all variables you can access from that container

egClusterCollectionAux.rawEta : vector

So in your analysis code (after setting up the TEvent and interface magic), you can access this variable from the

xAOD::CaloCluster object by calling rawEta.


14/22

Now lets look at some objects….



PACKAGE_DEP = EventLoop xAODRootAccess xAODEventInfo

In MyAnalysis/MyAnalysis/MyxAODAnalysis.h add as public:

int m_eventCounter; //!

remember the //! is important!!!!!

First some event information


15/22



In MyAnalysis/Root/MyxAODAnalysis.ccx

Near the top:

// EDM includes:

#include "xAODEventInfo/EventInfo.h"

In initialize() add:

// count number of events

m_eventCounter = 0;

In execute() :

// print every 100 events, so we know where we are:

if ( (m_eventCounter % 100) ==0 ) Info("execute()", "Event number = %i", m_eventCounter );m_eventCounter++;

//---------------------------- // Event information //---------------------------

const xAOD::EventInfo* eventInfo = 0;

if ( ! m_event->retrieve( eventInfo, "EventInfo").isSuccess() ){

Error("execute()", "Failed to retrieve event info collection. Exiting." );

return EL::StatusCode::FAILURE;

}

// check if the event is data or MC

// (many tools are applied either to data or MC)bool isMC = false;

// check if the event is MC

if (eventInfo->eventType( xAOD::EventInfo::IS_SIMULATION ) ){

isMC = true; // can do something with this later

}

rc find_packages

rc compile

you can copy

cp

/afs/cern.ch/work/h/hartj/public/xAODTutorial/MyxAOD

Analysis_1.cxx MyxAODAnalysis.cxx

Add includes

zero event counter

Increment event counter and print every 100

events

Access eventInfo and check if data or MC


16/22




PACKAGE_DEP = EventLoop xAODRootAccess xAODEventInfo xAODMuon

in MyAnalysis/Root/MyxAODAnalysis.ccx #include "xAODMuon/MuonContainer.h"

In execute()://------------

// MUONS

//------------

// get muon container of interest

const xAOD::MuonContainer* muons = 0;

if ( !m_event->retrieve( muons, "Muons" ).isSuccess() ){ // retrieve arguments: container type, container key

Error("execute()", "Failed to retrieve Muons container. Exiting." );


}

// loop over the muons in the container

xAOD::MuonContainer::const_iterator muon_itr = muons->begin();

xAOD::MuonContainer::const_iterator muon_end = muons->end();

for( ; muon_itr != muon_end; ++muon_itr ) {

Info("execute()", " original muon pt = %.2f GeV", ((*muon_itr)->pt() * 0.001)); // just to print out something

} // end for loop over muons

Offline muons:


17/22



Remember when we looked at the xAOD objects trigger muons were stored a xAODMuon with a different

key:

HLT_xAOD__MuonContainer_MuonEFInfo

in MyAnalysis/Root/MyxAODAnalysis.ccx in execute()://------------

// TRIGGER MUONS//------------

// get muon container of interest

const xAOD::MuonContainer* trmuons = 0;

if ( !m_event->retrieve( trmuons, "HLT_xAOD__MuonContainer_MuonEFInfo" ).isSuccess() ){ // retrieve arguments:

container type, container key

Error("execute()", "Failed to retrieve Muons container. Exiting." );


}

// loop over the muons in the container

xAOD::MuonContainer::const_iterator trmuon_itr = trmuons->begin();

xAOD::MuonContainer::const_iterator trmuon_end = trmuons->end();

for( ; trmuon_itr != trmuon_end; ++trmuon_itr ) {

Info("execute()", " trigger muon pt = %.2f GeV", ((*trmuon_itr)->pt() * 0.001)); // just to print out something

} // end for loop over trigger muons

Trigger muons:

you can copy

/afs/cern.ch/work/h/hartj/public/xAODTutorial/MyxAOD

Analysis_2.h and .cxx


18/22


Check twiki page for other objects and tools, e.g. jets, GRLTool:

https://twiki.cern.ch/twiki/bin/viewauth/AtlasComputing/SoftwareTutorialx

AODAnalysisInROOT

https://twiki.cern.ch/twiki/bin/viewauth/AtlasComputing/SoftwareTutorialxAODAnalysisInROOThttps://twiki.cern.ch/twiki/bin/viewauth/AtlasComputing/SoftwareTutorialxAODAnalysisInROOThttps://twiki.cern.ch/twiki/bin/viewauth/AtlasComputing/SoftwareTutorialxAODAnalysisInROOThttps://twiki.cern.ch/twiki/bin/viewauth/AtlasComputing/SoftwareTutorialxAODAnalysisInROOThttps://twiki.cern.ch/twiki/bin/viewauth/AtlasComputing/SoftwareTutorialxAODAnalysisInROOT


19/22


20/22

histograms are in root file:

submitDir/hist-valid1.117050.PowhegPythia_P2011C_ttbar.recon.AOD.e2658_s1967_s1964_r5856_tid01600225_00.root

also in hist/valid1.117050.PowhegPythia_P2011C_ttbar.recon.AOD.e2658_s1967_s1964_r5856_tid01600225_00.root so you can

access them with SampleHandler:

Add to ATestRun.cxx

// Fetch and plot our histogram - will pop up window for interactive running

SH::SampleHandler sh_hist;

sh_hist.load (submitDir + "/hist");

TH1 *hist = sh_hist.get (“valid1.117050.PowhegPythia_P2011C_ttbar.recon.AOD.e2658_s1967_s1964_r5856_tid01600225_00")-

>readHist ("h_muonPt");

hist->Draw ();

Then:

root -l 'ATestRun.cxx ("submitDir")'

and you should get a up a canvas popped up with your plot.

Histograms



21/22

TrigDecisionTool


Link to trigger talk in ATLAS software tutorial:

https://indico.cern.ch/event/329880/session/6/contribution/21/material/slides/0.pdf

Will look at accessing muon chains. Good place to check other signatures here:

https://svnweb.cern.ch/trac/atlasoff/browser/Trigger/TrigValidation/TrigValAlgs/tru

nk/src/TrigDecisionChecker.cxx

https://indico.cern.ch/event/329880/session/6/contribution/21/material/slides/0.pdfhttps://svnweb.cern.ch/trac/atlasoff/browser/Trigger/TrigValidation/TrigValAlgs/trunk/src/TrigDecisionChecker.cxxhttps://svnweb.cern.ch/trac/atlasoff/browser/Trigger/TrigValidation/TrigValAlgs/trunk/src/TrigDecisionChecker.cxxhttps://svnweb.cern.ch/trac/atlasoff/browser/Trigger/TrigValidation/TrigValAlgs/trunk/src/TrigDecisionChecker.cxxhttps://svnweb.cern.ch/trac/atlasoff/browser/Trigger/TrigValidation/TrigValAlgs/trunk/src/TrigDecisionChecker.cxxhttps://svnweb.cern.ch/trac/atlasoff/browser/Trigger/TrigValidation/TrigValAlgs/trunk/src/TrigDecisionChecker.cxxhttps://svnweb.cern.ch/trac/atlasoff/browser/Trigger/TrigValidation/TrigValAlgs/trunk/src/TrigDecisionChecker.cxxhttps://indico.cern.ch/event/329880/session/6/contribution/21/material/slides/0.pdfhttps://indico.cern.ch/event/329880/session/6/contribution/21/material/slides/0.pdf


22/22

Documents

XAOD Tutorial