Madweight requires as input a set of datacards and an LHCO file.

A LHCO file is a text file collecting basic info on all the events of the sample.

• It stores info about the type of particles in the event (muon, electron, jet, met) and relative pt, eta, phi, btag, ect.
• More info about the structure of LHCO files can be found at: http://madgraph.phys.ucl.ac.be/Manual/lhco.html

LHCO files can be converted from LHE files. To do this a script is available from MadGraph website. Download it in the working directory:

• wget https://cp3.irmp.ucl.ac.be/projects/madgraph/raw-attachment/wiki/MadWeightTool/lhe2lhco.py.txt
• mv lhe2lhco.py.txt lhe2lhco.py

LHCO files can converted also from EDM LHE files using a standard tool provided within the CMS framework (ExternalLHEAsciiDumper). Copy it and change the name of the input file:

• http://cmssw.cvs.cern.ch/cgi-bin/cmssw.cgi/CMSSW/GeneratorInterface/LHEInterface/test/testExternalLHEAsciiDumper_cfg.py?revision=1.2&view=markup

To convert root files to LHCO files a standard tool does not exist, because it depends on the structure of the user root file. A root/lhco converter script to convert tH analysis root ntuples in lhco file is going to be implemented and it will be posted here as soon as it will be ready.