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Getting started with ROOT

ROOT is a framework based on C++ that is specialized in processing data in High Energy Physics. Some of its central classes are

  • TTree to store data; typically variables are stored in branches for each entry/event (e.g. a proton-proton collision),
  • TH1 to make histograms,
  • TLorentzVector to make a four-vectors that you can boost, or add together with simply +,
  • TBrowser to browse ROOT files containing trees, histograms, …

Once installed, you can use its extensive libraries in your C++ code or in the ROOT command line. If you don't like C++ or pointers, it is also possible to use ROOT in python, a.k.a. pyROOT. This is definitely a good choice for doing simple things, such as making plots.

Always keep the the reference manual (a.k.a. class index) handy: it lists all the available classes and their methods, sometimes even examples.

Helpful materials to get started:

Protip: to quickly open root files in ROOT's TBrowser, use this predefined function, together with this macro:

function TBrowse { root -l "$@" ~/macros/myMacro.C; }
root/root.txt · Last modified: 2017/09/07 18:46 by iwn