ROOT. An interactive Object-Oriented framework and it's application to NA49 Analysis

Paper: 358
Session: C (talk)
Speaker: Roland, Gunther, Universitaet Frankfurt
Keywords: ?

"ROOT. An interactive Object-Oriented framework and it's application
to NA49 Analysis"

Rene Brun (*), Nenad Buncic (+), Valery Fine (@), Masaharu Goto (#),
Fons Rademakers (@), Gunther Roland (+), Andres Sandoval (@)

(*) CERN, (+) IKF Franfurt, (@) GSI Darmstadt, (#) HP Japan

The ROOT system is a modular Object Oriented framework for large scale
data analysis that replaces the ZEBRA, PAW and PIAF packages.

ROOT runs on Unix and Windows/NT systems. It contains a system
independent hierarchical OO database, a C++ interpreter, advanced
statistical analysis (multi dimensional histogramming, fitting and
minimisation algorithms) and visualisation tools.

The user interacts with ROOT via a graphical user interface, the
command line or batch scripts. The command and scripting language
is C++ (using the interpreter) and large scripts can be compiled and
dynamically linked. Special care has been put into the design of the
container classes and the I/O system for performance, system
independence and direct access to desired attributes of selected
without having to touch the bulk of the data.

The NA49 Experiment at the CERN SPS investigates central collisions of
heavy nuclei, detecting more than 1,600 charged particles per event. The
physics analysis of the reconstructed events (DSTs) requires fast
interactive access to data sets of several hundred GBytes. To achieve
the necessary throughput for an interactive multi-user system, a
version of ROOT has been implemented on a farm of dual Pentium Pro PCs
running Linux and interconnected with a Fast Ethernet switch.

The hardware and software design of this data mining cluster, on which
we achieve daily data turnover of several TBytes, will be discussed.