instructions.txt

//------------//
  Instructions
//------------//

----- How to set up the Lepton Efficiency Interface ------

1. Go to your CMSSW area, and do 

cmsenv

2. Then, do the following to clone the repositories (we will clone the repository with the ROOT files in the "data" folder). 

cd ${CMSSW_BASE}/src
git clone https://github.com/CMS-HTT/LeptonEff-interface.git HTT-utilities 
cd HTT-utilities/LepEffInterface/
git clone https://github.com/CMS-HTT/LeptonEfficiencies.git data 

3. Compile 

cd ${CMSSW_BASE}/src
scram b 


----- How to use the Lepton Efficiency Interface in your analysis -----

The interface provides a class, called ScaleFactor, whose .cc and .h files are located under 
LepEffInterface/src and LepEffInterface/interface, respectively. 

To use it in your analysis code, you should first perform the steps described above for the "set up". 
Then, in your analysis code, you should:

- include the header of the class

>> #include "HTT-utilities/LepEffInterface/interface/ScaleFactor.h"

- create the ScaleFactor object 

>> ScaleFactor * myScaleFactor = new ScaleFator();

- initialise the object, providing the full path to the ROOT file containing the efficiency you are interested in. 
(The ROOT files are located in the folders ${CMSSW_BASE}/src/HTT-utilities/LepEffInterface/data/ ). 

>> myScaleFactor->init_ScaleFactor("pathToRootFile/fileName.root");
 
- now, you can call the methods that return the efficiency in data, MC and the scale factor for a given (pt,eta). The (pt,eta) arguments passed should be double, and 
must be passed in the right order (pt first, then eta). E.g.:
>> double efficiency_data = myScaleFactor->get_EfficiencyData(pt, eta);
>> double efficiency_MC = myScaleFactor->get_EfficiencyMC(pt,eta);
>> double scaleFactor = myScaleFactor->get_ScaleFactor(pt,eta);

- last, you should include this line in your BuildFile.xml
>>  <use name="HTT-utilities/LepEffInterface"/>