ROOT Tutorial für HEPHY@CERN 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 http://root.cern.ch 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 * * http://root.cern.ch * * * ******************************************* ROOT 5.22/00d (branches/v5-22-00-patches@29532, Sep 25 2009, 00:59:00 on linux) CINT/ROOT C/C++ Interpreter version 5.16.29, 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 [0].x HelloWorld.C ROOT Scripte
Objekt Orientiert Wenn man etwas in ROOT machen will, muss man Objekte benutzen Objekt wird durch eine Klasse definiert Attribute Methoden
Inheritance TFile TRFIOFile TNetFile
Beispiel TFile * input = new Tfile::Open( http://... ) TFile is the main class that provides the interface TFile has a Factory Method Actual implementation is TNetFile
Shared Libraries Main Root Program Extension A Extension 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 * * http://root.cern.ch * * * ******************************************* ROOT 5.22/00d (branches/v5-22-00-patches@29532, Sep 25 2009, 00:59:00 on linux) CINT/ROOT C/C++ Interpreter version 5.16.29, 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/5.22.00dcms//tutorials/hsimple.c... hsimple : Real Time = 65.46 seconds Cpu Time = 0.46 seconds
$ROOTSYS/tutorials/tree/ntuple1.C
What is python? Python is an interpreted, object-oriented, highlevel 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 2.4.2 (#1, Mar 4 2008, 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