ROOT Tutorial für D. Liko

Was ist ROOT ? ● Am CERN entwickeltes Tool zur Analyse von Daten ● Funktionalität in vielen Bereichen ● Objekte ● C++ ● Skriptsprachen

Was kann ROOT

Verschiedene Aspekte ● C++ as script language with interpreter CINT ● Also python and ruby ● GUI for interactive visualization(TCanvas, TBrowser,...) ● I/O and analysis of large amountof data(TFile, TTree,...) ● Histograming, plotting, fits(TH1x, TGraph, TF1,...) ● Physics and mathematics(TMatrix, TLorentzVector, TMath,..) ● Objectorganisation(TCollection, TDirectory, TFolder,...) ● Parallel analysis via network(TProof) ● Vieles mehr ● hat alle Dokumentation

Setup ROOT ● Environment Variable ● PATH ● LD_LIBRARY_PATH ● ROOTSYS

Hello ROOT 1 [heplx02] /scratch/liko/workbook/CMSSW_3_3_1 $ root ******************************************* * * * W E L C O M E to R O O T * * * * Version 5.22/00d 27 July 2009 * * * * You are welcome to visit our Web site * * * * * ******************************************* ROOT 5.22/00d Sep , 00:59:00 on linux) CINT/ROOT C/C++ Interpreter version , Jan 08, 2008 Type ? for help. Commands must be C++ statements. Enclose multiple statements between { }. root [0] cout << "Hello World" << endl; Hello World root [1] printf("Hello World\n"); Hello World

Hello Root 2 root [0] TCanvas *c = new TCanvas("canvas1","Hello World Canvas",600,400) root [1] c->cd() root [2] TText *t = new TText(0.5, 0.5, "Hallo Welt") root [3] t->Draw()

ROOT Scripte root [0].x HelloWorld.C

Objekt Orientiert ● Wenn man etwas in ROOT machen will, muss man Objekte benutzen ● Objekt wird durch eine Klasse definiert ● Attribute ● Methoden

Inheritance TFile TRFIOFileTNetFile

Beispiel ● TFile * input = new Tfile::Open(“ ● TFile is the main class that provides the interface ● TFile has a Factory Methode ● Actual implementation is TNetFile

Shared Libraries Main Root Program Extension AExtension B

Histogramme ● Ein Histogramm ist eine komfortable Art Daten darzustellen und zu speichern. Im Prinzip besteht es aus einer Achse, die einen minimalen und ein maximalen Wert hat. Die Achse ist in eine Anzahl von Abschnitten (Bins) aufgeteilt ist, für die es jeweils einen Zähler gibt. ● Wenn man nun einen Wert in das Histogramm einfüllt, wird der Abschnitt gesucht, in den der Wert fällt, und dessen Zähler dann um eins erhöht. Man speichert also nicht mehr die Werte an sich sondern nur die Häufigkeiten, mit denen ein Wert innerhalb eines bestimmten Abschnittes vorkommt.

Beispiel Histogramm TCanvas *c = new TCanvas("canvas3", "Beispiel Histogram", 600, 400); c->cd(); TH1D *hist1D = new TH1D("hist1D", "Erstsemester", 10, 15., 25.); double werte[20] = {18., 17., 18., 18., 19., 23., 19., 18., 19., 18., 20., 21., 20., 18., 19., 20., 18., 19., 18., 18.}; for(int i = 0; i < 20; i++) { hist1D->Fill(werte[i]); } hist1D->GetXaxis()->SetTitle("Alter (Jahren)"); hist1D->GetYaxis()->SetTitle("Anzahl"); hist1D->Draw();

2D Histogramm TCanvas *c = new TCanvas("canvas4", "Beispiel 2D Histogram", 600, 400); c->cd(); TH2D *hist2D = new TH2D("hist2D", "Erstsemester 2D", 10, 15., 25., 10, 1.60, 2.00); double alter[20] = {18., 17., 18., 18., 19., 23., 19., 18., 19., 18., 20., 21., 20., 18., 19., 20., 18., 19., 18., 18.}; double groesse[20] = {1.76, 1.68, 1.90, 1.72, 1.87, 1.64, 1.78, 1.82, 1.75, 1.70, 1.72, 1.79, 1.80, 1.75, 1.89, 1.68, 1.77, 1.77, 1.87, 1.72}; for(int i = 0; i < 20; i++) { hist2D->Fill(alter[i], groesse[i]); } hist2D->GetXaxis()->SetTitle("Alter (Jahren)"); hist2D->GetYaxis()->SetTitle("Groesse (m)"); hist2D->GetZaxis()->SetTitle("Anzahl"); hist2D->Draw("LEGO2");

Daten mit Fehlern double zeit[4] = {2., 4., 6., 8.}; double geschw[4] = {10., 12., 15., 19.}; double geschwFehler[4] = {1., 1.2, 1.6, 1.4}; TGraphErrors *gr = new TGraphErrors(4, zeit, geschw, 0, geschwFehler); gr->SetTitle(""); gr->SetMarkerStyle(22); gr->GetXaxis()->SetTitle("Zeit (s)"); gr->GetYaxis()->SetTitle("Geschwindigkeit (m/s)"); gr->Draw("AP");

Ntuple and TTree ● Ntuple ● Most simple structure to store data ● Data are Tuples ● Ttree ● Advanced data structure to store all kind of Objects ● Ntuples ● Histograms, Canvas, etc ● Event Data

Create and Examine Ntuple root $ROOTSYS/tutorials/hsimple.C ******************************************* * * * W E L C O M E to R O O T * * * * Version 5.22/00d 27 July 2009 * * * * You are welcome to visit our Web site * * * * * ******************************************* ROOT 5.22/00d Sep , 00:59:00 on linux) CINT/ROOT C/C++ Interpreter version , Jan 08, 2008 Type ? for help. Commands must be C++ statements. Enclose multiple statements between { }. root [0] Processing /afs/hephy.at/project/cms/software/slc4_ia32_gcc345/lcg/root/ d- cms//tutorials/hsimple.C... hsimple : Real Time = seconds Cpu Time = 0.46 seconds

$ROOTSYS/tutorials/tree/ntuple1.C

What is python ? ● Python is an interpreted, object-oriented, high- level programming language with dynamic semantics. ● Its high-level built in data structures, combined with dynamic typing and dynamic binding, make it very attractive for Rapid Application Development, as well as for use as a scripting or glue language to connect existing components together.

Python Hello World [heplx02] /scratch/liko/workbook/CMSSW_3_3_1 $ python Python (#1, Mar , 22:56:43) [GCC 3.4.5] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> print "hello World" hello World >>>

Python and ROOT ● ROOT and Python are often used together ● Same objects ● Different syntax ● python $ROOTSYS/tutorials/pyroot/hsum.py