Getting started with the CMS software
Login to a machine and define the CMS environment variables
- login to the lxpub2 or lxpub3 machine
e.g: ssh -X username@lxpub2.iihe.ac.be
- source the CMS environment
setenv VO_CMS_SW_DIR /msa3/cmssoft source $VO_CMS_SW_DIR/cmsset_default.csh ## initialize the cms env
- define the code cvs repository
alias cmscvsroot 'source $CMS_PATH/utils/cmscvsroot.csh' cmscvsroot CMSSW
Prepare the CMSSW working area
Follow these steps:
- make yourself a directory on /beo5
mkdir /beo5/whoami
- go to that directory
cd /beo5/whoami
- install a CMSSW working area and go to the src subdirectory
scramv1 p CMSSW CMSSW_1_0_1; cd CMSSW_1_0_1/src
Get the necessary code and compile it
- log onto the cvs code server; type 98passwd as password
cvs login CVS password:
- checkout the source code of the libraries that you want to use or modify. Here we will use the interface to the Pythia event generator
cvs co -r CMSSW_1_0_1 IOMC/GeneratorInterface/test; cd IOMC/GeneratorInterface/test
- compile the code
eval scramv1 runtime -csh scramv1 b
Run CMSSW interactively and produce a few events
The parameters for CMSSW are specified in a text file called the config file. This file can include other config files using the #include directive. Let's run the standard example which produces Higgs events decaying into 4 muons in the final state, and plots a few distributions:
cmsRun pythiaHZZ4mu+analysis.cfg
You should see two root files appear: one with the generated events stored in HepMC format, and one with the distribution histograms. Did it work ? In case of problems, do not hesitate to contact Jan Heyninck or Pascal Vanlaer.
At this stage you should learn more about CMSSW by studying the CMSSW Workbook, chapters 2 to 4.