#include "fastjet/PseudoJet.hh"
#include "fastjet/ClusterSequenceArea.hh"
#include "fastjet/ClusterSequencePassiveArea.hh"
#include "fastjet/config.h"
#include "fastjet/SISConePlugin.hh"
#include <iostream>
#include <sstream>
#include <vector>
Go to the source code of this file.
Functions | |
void | print_jets (const fastjet::ClusterSequenceAreaBase &clust_seq, const vector< fastjet::PseudoJet > &unsorted_jets) |
a function that pretty prints a list of jets | |
int | main (int argc, char **argv) |
an example program showing how to use fastjet |
int main | ( | int | argc, | |
char ** | argv | |||
) |
an example program showing how to use fastjet
Definition at line 67 of file fastjet_areas.cc.
References Best, kt_algorithm, passive_area, and print_jets().
00067 { 00068 00069 vector<fastjet::PseudoJet> input_particles; 00070 00071 // read in input particles 00072 double px, py , pz, E; 00073 while (cin >> px >> py >> pz >> E) { 00074 // create a fastjet::PseudoJet with these components and put it onto 00075 // back of the input_particles vector 00076 input_particles.push_back(fastjet::PseudoJet(px,py,pz,E)); 00077 } 00078 00079 // create an object that represents your choice of jet algorithm, and 00080 // the associated parameters 00081 double Rparam = 1.0; 00082 fastjet::Strategy strategy = fastjet::Best; 00083 fastjet::JetDefinition jet_def(fastjet::kt_algorithm, Rparam, strategy); 00084 //fastjet::JetDefinition jet_def(fastjet::cambridge_algorithm, Rparam, strategy); 00085 //fastjet::JetDefinition jet_def(fastjet::antikt_algorithm, Rparam, strategy); 00086 //fastjet::JetDefinition jet_def(new fastjet::SISConePlugin(Rparam,0.75)); 00087 00088 // create an object that specifies how we to define the area 00089 fastjet::AreaDefinition area_def; 00090 bool use_voronoi = false; 00091 if (!use_voronoi) { 00092 double ghost_etamax = 7.0; 00093 double ghost_area = 0.05; 00094 int active_area_repeats = 1; 00095 // alternative settings for more precision: 00096 // reducing ghost area gives better sensitivity to the exact edges of the jet 00097 //double ghost_area = 0.01; 00098 // increasing the repeats is useful in sparse events 00099 //int active_area_repeats = 100; 00100 00101 // now create the object that holds info about ghosts, and from that 00102 // get an area definition 00103 fastjet::GhostedAreaSpec ghost_spec(ghost_etamax, active_area_repeats, 00104 ghost_area); 00105 area_def = fastjet::AreaDefinition(fastjet::passive_area,ghost_spec); 00106 //area_def = fastjet::AreaDefinition(fastjet::active_area,ghost_spec); 00107 } else { 00108 double effective_Rfact = 1.0; 00109 area_def = fastjet::VoronoiAreaSpec(effective_Rfact); 00110 } 00111 00112 // run the jet clustering with the above jet definition 00113 fastjet::ClusterSequenceArea clust_seq(input_particles, 00114 jet_def, area_def); 00115 // you can also run the individual area classes directly 00116 //fastjet::ClusterSequencePassiveArea clust_seq(input_particles, jet_def, 00117 // area_def.ghost_spec()); 00118 00119 // you may want to find out how much area in a given range (|y|<range) 00120 // is empty of real jets (or corresponds to pure "ghost" jets). 00121 //double range = 4.0; 00122 //cout << clust_seq.empty_area(range) << endl; 00123 //cout << clust_seq.n_empty_jets(range) << endl; 00124 00125 // tell the user what was done 00126 cout << "Jet definition was: " << jet_def.description() << endl; 00127 cout << "Area definition was: " << area_def.description() << endl; 00128 cout << "Strategy adopted by FastJet was "<< 00129 clust_seq.strategy_string()<<endl<<endl; 00130 00131 // extract the inclusive jets with pt > 5 GeV, sorted by pt 00132 double ptmin = 5.0; 00133 vector<fastjet::PseudoJet> inclusive_jets = clust_seq.inclusive_jets(ptmin); 00134 00135 // print them out 00136 cout << "Printing inclusive jets with pt > "<< ptmin<<" GeV\n"; 00137 cout << "---------------------------------------\n"; 00138 print_jets(clust_seq, inclusive_jets); 00139 cout << endl; 00140 00141 00142 cout << "Number of unclustered particles: " 00143 << clust_seq.unclustered_particles().size() << endl; 00144 00145 00146 }
void print_jets | ( | const fastjet::ClusterSequenceAreaBase & | clust_seq, | |
const vector< fastjet::PseudoJet > & | unsorted_jets | |||
) |
a function that pretty prints a list of jets
a function that pretty prints a list of jets, and performs the subtraction in two different ways, using a generic ClusterSequenceAreaBase type object.
Definition at line 151 of file fastjet_areas.cc.
References fastjet::d0::inline_maths::phi(), and sorted_by_pt().
Referenced by main(), and run_jet_finder().
00152 { 00153 00154 // sort jets into increasing pt 00155 vector<fastjet::PseudoJet> jets = sorted_by_pt(unsorted_jets); 00156 00157 printf(" ijet rap phi Pt area +- err\n"); 00158 for (size_t j = 0; j < jets.size(); j++) { 00159 00160 double area = clust_seq.area(jets[j]); 00161 double area_error = clust_seq.area_error(jets[j]); 00162 00163 printf("%5u %9.5f %8.5f %10.3f %8.3f +- %6.3f\n",j,jets[j].rap(), 00164 jets[j].phi(),jets[j].perp(), area, area_error); 00165 } 00166 00167 00168 }