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ROOT Framework OOP

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WHERE is ROOT

http://root.cern.ch

http://root.cern.ch/http://root.cern.ch/

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WHAT is ROOT

http://en.wikipedia.org/wiki/ROOT

CERN maintained a program library writtenin FORTRAN for many years; developmentand maintenance were discontinued in

2003 in favour of ROOT, written in C++.ROOT development was initiated by RenBrun and Fons Rademakers in 1994.

Why C/C++:

Scalability - Incapsulation, Polymorphism,Inheritance - Steep learning curve, OS

dependentBorn as the orphan child, currently suffers frompositive discrimination, but indeed ROOT doesmany things...

http://en.wikipedia.org/wiki/ROOThttp://en.wikipedia.org/wiki/ROOT

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WHAT is ROOT (2)

The backbone of the ROOT architecture is alayered class hierarchy with, currently, around1200 classes grouped in about 60 frameworks(libraries) divided in 19 main categories(modules). This hierarchy is organized in a

mostly single-rooted class library, that is, mostof the classes inherit from a common baseclass TObject.

ROOT Base, Containers (Data), Physics,Matrix, Histograms, Minimization, Trees,2D/3D Graphics, Image processing, Detector

geometry, GUI, SQL interface

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Save data. You can save your data (and any C++ object) in a compressed binary form in a ROOTfile. The object format is also saved in the same file. ROOT provides a data structure that isextremely powerful for fast access of huge amounts of data - orders of magnitude faster than anydatabase.

Access data. Data saved into one or several ROOT files can be accessed from your PC, from theweb and from large-scale file delivery systems used e.g. in the GRID. ROOT trees spread overseveral files can be chained and accessed as a unique object, allowing for loops over hugeamounts of data.

Process data. Powerful mathematical and statistical tools are provided to operate on your data.The full power of a C++ application and of parallel processing is available for any kind of datamanipulation. Data can also be generated following any statistical distribution, making it possibleto simulate complex systems.

Show results. Results are best shown with histograms, scatter plots, fitting functions, etc. ROOTgraphics may be adjusted real-time by few mouse clicks. High-quality plots can be saved in PDFor other format(image, c macro, etc).

Interactive or built application. You can use the CINT C++ interpreter or Python for yourinteractive sessions and to write macros, or compile your program to run at full speed. In bothcases, you can also create a GUI.

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Introducing ROOT Team

Rene Brun

Fons Rademakers

Andrei Gheata

Andrei works since 2001 in the offline group of the ALICE experiment. He is an experimentalnuclear physicist who worked before ALICE on data analysis for heavy-ion experiments inemulsions. In 2000 he started collaborating with the ROOT project and implemented theTreeViewer interface. Andrei is currently the main developer of the ROOT geometry package. He

integrated the geometry in the Virtual Monte Carlo framework by developing interfaces for theGEANT3, GEANT4 and FLUKA particle transport engines.

Extremely active, only a bunch of people (physicists, not programmers), large community

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Hands-On histograms

Starting ROOT

Create a simple histogram

Fit the histogram (params, stats...)

Save the results (.C, .root, image)

Resuming work

Command line Vs. Interactive tools

Other

2D/3D histograms, demos.C

More examples:http://root.cern.ch/drupal/content/graphics-exampleshttp://root.cern.ch/drupal/category/image-galleries/basic-graphicshttp://root.cern.ch/drupal/category/image-galleries/data-analysis-visualization

http://root.cern.ch/drupal/content/graphics-exampleshttp://root.cern.ch/drupal/category/image-galleries/basic-graphicshttp://root.cern.ch/drupal/category/image-galleries/data-analysis-visualizationhttp://root.cern.ch/drupal/category/image-galleries/data-analysis-visualizationhttp://root.cern.ch/drupal/category/image-galleries/basic-graphicshttp://root.cern.ch/drupal/content/graphics-examples

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WHO uses ROOT officially!

Running Experiments:ALICE, Antares, ATLAS, BaBar, BRAHMS,CB-ELSA/TAPS, CDF, CMS, COMPASS, DZero, H1, LHCb,MINERA, MINOS, NEXT, PEN, PHENIX, PHOBOS, STAR, T2K,ZEUS, CRESST, OPERA

Future Experiments: NOA, CBM, PANDA, BELLE II, Long BaselineNeutrino Experiment (LBNE)

Astrophysics Experiments: AMS, ANTARES, DMTPC, Fermi,ICECUBE, H.E.S.S., MAGIC, Milagro (experiment), Pierre AugerObservatory, VERITAS, PAMELA, PoGOLite

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WHO uses ROOT (2)

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WHO uses ROOT (3)

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WHO uses ROOT (4)

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WHO uses ROOT (5)

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WHO uses ROOT (6)

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WHO uses ROOT (7)

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Where ROOT meets Experiment

Large data sets ~Petabytes/year collisions event particles

Planning the experiment detector simulations, detector

response via simulated data

RAW data Physicalinformation (tracks, particles)via parallel processing, gridcomputing RAW LTR->GTR ESD-trees

Analysis, model datacomparisons

Papers

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What Experiments do

Take ROOT Framework as base

Develop ROOT specific code for:

Online monitoring

Detectors (calibrations, response)

Data storage

Workflow for reducing data

ANALYSIS tools

Example: brat, cbmroot, aliroot

Containers(DATA classes) Modules(workhorses, no DATA)

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Hands-On binary objects

Multiple source compilation

Configure Makefile Shared Objects , Binaries

ROOT examples osc2root

SO in ROOT, BRAT, CBMROOT, ALIROOT

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ROOT treesHighly optimized datastructures for fast dataaccess and large storagesize, with sequentialaccess to the data

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Hands-On tree analysis

Interpreted scripts

TreeViewer

Tree projections Treeiteration

Compiled code with ACLIC

Benchmarking

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Event Visualization

Detailed experiment geometry

Tracks/Hits

CBM event viewer

Other examples:

http://root.cern.ch/drupal/category/image-galleries/detectors

http://root.cern.ch/drupal/category/image-galleries/events-displays-root-applications

http://root.cern.ch/drupal/category/image-galleries/detectorshttp://root.cern.ch/drupal/category/image-galleries/events-displays-root-applicationshttp://root.cern.ch/drupal/category/image-galleries/events-displays-root-applicationshttp://root.cern.ch/drupal/category/image-galleries/detectors

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Hands-On EVE

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PROOF

Parallel ROOT Framework = distributetasks like event generation on multi-coremachines

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Hands-On PROOF

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Serious PROOF ?

4 x 4 quadCore = 16 CPU x 10 BLADES = 160 CPU's

16 Gbytes DDR2 RAM / blade

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Approach

Learn ENGLISH

Learn PHYSICS

Learn PROGRAMMING

Go to many conferences (grantscovering up to 100% expenses)

Granted good jobs

The question is NOTWhat can ROOT do for me?But What can I do for ROOT?

ProgrammerREPEAT over and over thesame solutions + PATIENCE forfinding bugs

Physicistinovation, open mind, getproblems esence, etc

BLEEDING EDGEcombination !!!

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Instead of summary...

Where to find these slides:

http://brahms.fizica.unibuc.ro/teaching/rootpresentation.pdf

THANK YOU!

and WE are waiting for you when you're ready :-)

http://brahms.fizica.unibuc.ro/teaching/rootpresentation.pdfhttp://brahms.fizica.unibuc.ro/teaching/rootpresentation.pdf