= Reading CMS Files =

== Generator Events in CMS ROOT Files ==

It is possible to run Delphes on the generator events stored in CMS ROOT files (FEVT, RECO, AOD).

More details on the generator event format can be found at

https://twiki.cern.ch/twiki/bin/view/CMSPublic/WorkBookGenParticleCandidate

== Setting up CMSSW Computing Environment ==

The instructions on how to setup CMSSW work area and runtime environment can be found at

https://twiki.cern.ch/twiki/bin/view/CMSPublic/WorkBookSetComputerNode

== Building Delphes and DelphesCMSFWLite ==

Commands to download and build Delphes: 

{{{
export LD_LIBRARY_PATH=.:$LD_LIBRARY_PATH

wget http://cp3.irmp.ucl.ac.be/downloads/Delphes-3.3.1.tar.gz
tar -zxf Delphes-3.3.1.tar.gz

cd Delphes-3.3.1
make -j 4
}}}

== Running DelphesCMSFWLite ==

When running '''{{{DelphesCMSFWLite}}}''' without parameters or when supplying an invalid command line, the following message will be shown:
{{{
./DelphesCMSFWLite
 Usage: DelphesCMSFWLite config_file output_file input_file(s)
 config_file - configuration file in Tcl format,
 output_file - output file in ROOT format,
 input_file(s) - input file(s) in ROOT format.
}}}

Running Delphes with CMS ROOT input files: 
{{{
./DelphesCMSFWLite cards/delphes_card_CMS.tcl delphes_output.root input.root
}}}