From Gridkaschool

Tutorial documentation

You can find tutorial slides in PDF format at File:GridKa2012 root proof.pdf.

Please visit this page for complete documentation for this tutorial.


Arsen Hayrapetyan, Martin Vala


ROOT is an object-oriented framework for large-scale data analysis. PROOF, the Parallel Root Facility, is an extension of ROOT which enables interactive parallel large-scale analysis on a cluster. PROOF Lite, a dedicated version of PROOF, allows to analyse the data on a multi-core computer. In the first part of ROOT/PROOF tutorial the participants will be introduced to ROOT and tools for analysis and visualisation of the data on a desktop machine. Participants will learn how to design and use a custom event class for analysis of data stored in ROOT tree structure. This will be followed by the second part where the structure of the PROOF system and tree/selector-based analysis will be explained. Participants will run analysis tasks on multi-core desktop systems and on a dedicated PROOF cluster in practical exercises.


  • Login/password provided by School organisers in your personal information sheet to connect to UI (user interface) machines. Machines will have ROOT software installed.
  • If you plan to use your laptop instead of UI you should have installed ROOT on the laptop. You can download ROOT here.

Assigned excercise machines -> PROOF Master

Presentation outline


  • Introduction to ROOT
  • Basic ROOT features: Data containers, visualisation, GUI, CLI
  • Trees and chains
  • Events. Sample event class creation
  • Selectors
  • Analysis of data stored in a chain


  • Introduction to PROOF
  • PROOF analysis schema
  • Analysing data with PROOF Lite
  • PAR files
  • Datasets
  • Analysis with PROOF


  1. Using ROOT CLI
  2. Creation of 1-D histogram with ROOT macro
  3. Using ROOT GUI
  4. Creation of a sample event class
  5. Creation of a tree containing events from previous exercise
  6. Tree content visualisation
  7. Creation of a selector for data analysis
  8. Analysis of the data stored in a chain, locally
  9. Creation of a PAR file
  10. Data analysis with PROOF Lite
  11. Dataset management
  12. Data analysis with PROOF