CMS-OpenData-analysis

(Note : There is a detailed user manual written for anyone wanting to dig a little deeper.)

How to run the analysis codes:

The analysis codes are kept in the directory ./analysis codes. Go to the directory and compile the code from the ROOT prompt by doing the following.

.L AnaOpenData.C+

The + makes sure that it creates an .so file in the same directory, which can be used later. After this step, the compiled library is loaded, and it can be used from the ROOT prompt. Next, the driver file is executed to feed the appropriate values to the input-output parameters and run the analysis.

.x driver.C(0)

That's it!
The verbosity number in the Process() function of the main C script can be tweaked to display a status-update after some number of processed events.

Note : This particular set of codes works with a specific structure of the input ntuple. If there is any change made to the branches of the flat ntuple, The TTreeReader method in the AnaOpenData.h file needs to be modified accordingly. Otherwise it leads to "Segmentation error" during runtime.

How to make ntuples:

The NTuple maker codes can be found in the ./NtupleMaker directory.

For CMS-OpenData-Virtual Machine:

Requirements:

1. CMS-OpenData-Virtual Machine should be up and running on the system.
2. CMS Environment should be set up with version CMSSW_5_3_32.
3. The NTupleMaker files shall be placed in the directory ./CMSSW_5_3_32/src/

For more information on how to set up the CMS-OpenData Virtual Machine visit (https://opendata.cern.ch/docs/about-cms)

Note : For setting up the CMS environment, CMSSW_5_3_32, open CMS Shell, set up the software architecture and version by doing export SCRAM_ARCH=slc6_amd64_gcc472, set up a new release area for CMSSW_5_3_32 by doing cmsrel CMSSW_5_3_32.

Steps to make the NTuples:

1. Open the CMS Shell Terminal and locate the NTupleMaker directory.
2. Set up the runtime environment needed to work with CMSSW by doing:

cmsenv

3. Compile the code by doing:

scram b -j 8

4. Open the ./python directory to find the python exectuable configuration file, masterntuplemaker_cfg.py. This file is going to give the output root file.
5. To execute the configuration file and get the output NTuple do:

For Data:

For 7TeV:

cmsRun masterntuplemaker_cfg.py isData=True is7TeV=True nEvents=1000

For 8TeV:

cmsRun masterntuplemaker_cfg.py isData=True is8TeV=True nEvents=1000

For MC:

cmsRun masterntuplemaker_cfg.py isData=False nEvents=1000

6. That's it. The output NTuples should be available in the ./output_files directory.

Getting the output ROOT files to the local machine:

1. Open the Outer Shell Terminal (not the CMS Terminal) and locate the ./output_files directory.
2. Now use the secure copy command scp to move the file to the desired local machine directory.

scp -C [output_filename.root] username_localmachine@[Host_IP_Address]:/home/username_localmachine/desired/path/to/store/the/output_file

3. Now one can access the NTuples in their local machine and run the Analysis Codes.

For Docker:

Requirements:

1. Docker-Desktop should be up and running on the system.
2. Docker container image containing CMSSW_5_3_32 should be installed.
3. The NTupleMaker files shall be placed in the directory ./CMSSW_5_3_32/src/

For more information on how to set up the Docker-Desktop visit (https://opendata.cern.ch/docs/cms-guide-docker)

Steps to make the NTuples:

1. Open the terminal and run docker start -i [name_of_container]
2. Git Clone this repository in the directory/code/CMSSW_5_3_32/src/. Navigate to director /code/CMSSW_5_3_32/src/CMS-OpenData-analysis/NtupleMaker/
3. Compile the code by doing:

scram b -j 8

4. Open the ./python directory to find the python exectuable configuration file, masterntuplemaker_cfg.py. This file is going to give the output root file.
5. To execute the configuration file and get the output NTuple do:

For Data:

For 7TeV:

cmsRun masterntuplemaker_cfg.py isData=True is7TeV=True nEvents=1000

For 8TeV:

cmsRun masterntuplemaker_cfg.py isData=True is8TeV=True nEvents=1000

For MC:

cmsRun masterntuplemaker_cfg.py isData=False nEvents=1000

6. That's it. The output NTuples should be available in the ./output_files directory.

Getting the output ROOT files to the local machine:

1. Open another terminal on your local machine.
2. Do the following:

if Data:

docker cp CMSSW_5_3_32:/code/CMSSW_5_3_32/CMS-OpenData-analysis/NtupleMaker/ouput_files/CMS_Data_AOD.root  /home/username_localmachine/desired/path/to/store/the/output_file

if MC:

docker cp CMSSW_5_3_32:/code/CMSSW_5_3_32/CMS-OpenData-analysis/NtupleMaker/ouput_files/CMS_MC_AODSIM.root  /home/username_localmachine/desired/path/to/store/the/output_file

3. Now one can access the NTuples in their local machine and run the Analysis Codes.