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**Abstract**

ROOT is a software framework for data analysis and I/O: a powerful tool to cope
with the demanding tasks typical of state of the art scientific data analysis.
Among its prominent features are an advanced graphical user
interface, ideal for interactive analysis, an interpreter for the C++
programming language, for rapid and efficient prototyping and a
persistency mechanism for C++ objects, used also to write every year
petabytes of data recorded by the Large Hadron Collider experiments.
This introductory guide illustrates the main features of ROOT which are
relevant for the typical problems of data analysis: input and plotting of data
from measurements and fitting of analytical functions.

*Original Authors*
- D. Piparo
- G. Quast
- M. Zeise

