FastJet 3.0.2
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00001 //---------------------------------------------------------------------- 00002 /// \file 00003 /// \page Example01 01 - basic usage example 00004 /// 00005 /// fastjet basic example program: 00006 /// simplest illustration of the usage of the basic classes: 00007 /// fastjet::PseudoJet, fastjet::JetDefinition and 00008 /// fastjet::ClusterSequence 00009 /// 00010 /// run it with : ./01-basic < data/single-event.dat 00011 /// 00012 /// Source code: 01-basic.cc 00013 //---------------------------------------------------------------------- 00014 00015 //STARTHEADER 00016 // $Id: 01-basic.cc 2684 2011-11-14 07:41:44Z soyez $ 00017 // 00018 // Copyright (c) 2005-2011, Matteo Cacciari, Gavin P. Salam and Gregory Soyez 00019 // 00020 //---------------------------------------------------------------------- 00021 // This file is part of FastJet. 00022 // 00023 // FastJet is free software; you can redistribute it and/or modify 00024 // it under the terms of the GNU General Public License as published by 00025 // the Free Software Foundation; either version 2 of the License, or 00026 // (at your option) any later version. 00027 // 00028 // The algorithms that underlie FastJet have required considerable 00029 // development and are described in hep-ph/0512210. If you use 00030 // FastJet as part of work towards a scientific publication, please 00031 // include a citation to the FastJet paper. 00032 // 00033 // FastJet is distributed in the hope that it will be useful, 00034 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00035 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00036 // GNU General Public License for more details. 00037 // 00038 // You should have received a copy of the GNU General Public License 00039 // along with FastJet. If not, see <http://www.gnu.org/licenses/>. 00040 //---------------------------------------------------------------------- 00041 //ENDHEADER 00042 00043 #include "fastjet/ClusterSequence.hh" 00044 #include <iostream> // needed for io 00045 #include <cstdio> // needed for io 00046 00047 using namespace std; 00048 00049 /// an example program showing how to use fastjet 00050 int main(){ 00051 00052 // read in input particles 00053 //---------------------------------------------------------- 00054 vector<fastjet::PseudoJet> input_particles; 00055 00056 double px, py , pz, E; 00057 while (cin >> px >> py >> pz >> E) { 00058 // create a fastjet::PseudoJet with these components and put it onto 00059 // back of the input_particles vector 00060 input_particles.push_back(fastjet::PseudoJet(px,py,pz,E)); 00061 } 00062 00063 00064 // create a jet definition: 00065 // a jet algorithm with a given radius parameter 00066 //---------------------------------------------------------- 00067 double R = 0.6; 00068 fastjet::JetDefinition jet_def(fastjet::antikt_algorithm, R); 00069 00070 00071 // run the jet clustering with the above jet definition 00072 //---------------------------------------------------------- 00073 fastjet::ClusterSequence clust_seq(input_particles, jet_def); 00074 00075 00076 // get the resulting jets ordered in pt 00077 //---------------------------------------------------------- 00078 double ptmin = 5.0; 00079 vector<fastjet::PseudoJet> inclusive_jets = sorted_by_pt(clust_seq.inclusive_jets(ptmin)); 00080 00081 00082 // tell the user what was done 00083 // - the description of the algorithm used 00084 // - extract the inclusive jets with pt > 5 GeV 00085 // show the output as 00086 // {index, rap, phi, pt} 00087 //---------------------------------------------------------- 00088 cout << "Ran " << jet_def.description() << endl; 00089 00090 // label the columns 00091 printf("%5s %15s %15s %15s\n","jet #", "rapidity", "phi", "pt"); 00092 00093 // print out the details for each jet 00094 for (unsigned int i = 0; i < inclusive_jets.size(); i++) { 00095 printf("%5u %15.8f %15.8f %15.8f\n", 00096 i, inclusive_jets[i].rap(), inclusive_jets[i].phi(), 00097 inclusive_jets[i].perp()); 00098 } 00099 00100 return 0; 00101 }