This course targets scientists and engineers with little or no experience of ROOT. The basics of the package are covered as well as high level concepts of C++ and Python.

This work is licensed under a Creative Commons Attribution 4.0 International License.

You can find the slides of the course here.

Participants of the ROOT basic course need to perform the following preparation actions prior to the course.

Participants have at their disposal a virtual machine image where ROOT is installed. With this image, they can instantiate a virtual machine and execute the ROOT examples and exercises that will be shown during the course.

In order to install the ROOT Virtual Machine image in their own machine, participants can follow these steps:

• Download and install VirtualBox (Note: on some recent macs 5.2 versions of VirtualBox are rather slow. If this is the case for you, you can try 5.0.40 instead): https://www.virtualbox.org/wiki/Downloads
• Download the ROOT VM appliance from this link: https://cernbox.cern.ch/index.php/s/ZF5pffhZuZjwgAI
• Import the ROOT VM appliance from VirtualBox: https://docs.oracle.com/cd/E26217_01/E26796/html/qs-import-vm.html

SWAN (Service for Web-based ANalysis) is a CERN service that allows interactive edition and execution of ROOT programs from a web browser.

In order to be able to connect and use the SWAN service during the course, participants need to make sure that:

• They have a CERN account that is associated to a computing group. They can check if they belong to a computing group at https://account.cern.ch/account/CERNAccount/AccountStatus.aspx. If a participant does not belong to any computing group, she can subscribe to the default computing group following these instructions: https://resources.web.cern.ch/resources/Help/?kbid=067030
• They have created a CERNBox account. In order to create it, they just need to connect and authenticate with their CERN username and password at https://cernbox.cern.ch
• They can log in to SWAN with their CERN username and password: https://swan.cern.ch

1. Introduction

• What is ROOT?
• Usage patterns and example applications
• Structure and elements of ROOT
• Setting up the exercise environment

2. The C++ Interpreter

• C++ Crash course
• The ROOT prompt
• ROOT as a calculator and notepad for your C++
• Interpreter commands
• Macros
• Exercises

3. Histograms, Graphs and Functions

• Histograms
• Graphs
• Functions
• Basic interaction with the canvas, plotting, styling
• Exercises

4. Graphics

• Creating a nice plot: best practices, axes, legends, styles, colours, markers and fonts
• Introduction to JSROOT
• Exercises

5. Fitting

• Likelihood and Chi2 maximisation
• Introduction to fitting and common fitting problems
• Building sophisticated fit functions
• Interface to Minimization
• Using the ROOT Fit GUI
• Random number generation
• Exercises

6. Python Interface

• Python crash course
• Mapping C++ to Python with PyROOT: elements of the ROOT Python "bindings"
• Exercises

7. ROOTBooks

• Complement the macro, prompt and script approach with a web-based solution
• Create a nice ROOTBook: best practices, plotting
• JSROOT in ROOTBooks
• ROOTBooks at CERN: SWAN service
• Exercises

8. Working with Files

• The problem of input and output of data
• Elements of file structure and format
• Write and read objects
• The TBrowser
• Exercises

9. Working with Columnar Data

• Two storage options: row- and column-wise
• TDataFrame: the handle on the ROOT (and not only) columnar data
• Exercises

10. Developing packages using ROOT

• Setting up the environment
• Linking libraries, finding headers: the root-config script
• Exercises