fastjet_example.cc File Reference

#include "fastjet/PseudoJet.hh"
#include "fastjet/ClusterSequence.hh"
#include <iostream>
#include <sstream>
#include <vector>

Include dependency graph for fastjet_example.cc:

fastjet/PseudoJet.hhfastjet/ClusterSequence.hhfastjet/internal/numconsts.hhfastjet/internal/base.hhfastjet/internal/DynamicNearestNeighbours.hhfastjet/Error.hhfastjet/JetDefinition.hh

Go to the source code of this file.

Functions

void print_jets (const fastjet::ClusterSequence &clust_seq, const vector< fastjet::PseudoJet > &jets)
 a function that pretty prints a list of jets
int main (int argc, char **argv)
 an example program showing how to use fastjet


Function Documentation

int main ( int  argc,
char **  argv 
)

an example program showing how to use fastjet

Definition at line 55 of file fastjet_example.cc.

References fastjet::Best, fastjet::JetDefinition::description(), fastjet::E_scheme, fastjet::ClusterSequence::exclusive_jets(), fastjet::ClusterSequence::inclusive_jets(), fastjet::kt_algorithm, print_jets(), and fastjet::ClusterSequence::strategy_string().

00055                                   {
00056   
00057   vector<fastjet::PseudoJet> input_particles;
00058   
00059   // read in input particles
00060   double px, py , pz, E;
00061   while (cin >> px >> py >> pz >> E) {
00062     // create a fastjet::PseudoJet with these components and put it onto
00063     // back of the input_particles vector
00064     input_particles.push_back(fastjet::PseudoJet(px,py,pz,E)); 
00065   }
00066   
00067   // create an object that represents your choice of jet algorithm and 
00068   // the associated parameters
00069   double Rparam = 1.0;
00070   fastjet::Strategy strategy = fastjet::Best;
00071   fastjet::RecombinationScheme recomb_scheme = fastjet::E_scheme;
00072   fastjet::JetDefinition jet_def(fastjet::kt_algorithm, Rparam, recomb_scheme, strategy);
00073 
00074   // run the jet clustering with the above jet definition
00075   fastjet::ClusterSequence clust_seq(input_particles, jet_def);
00076 
00077   // tell the user what was done
00078   cout << "Ran " << jet_def.description() << endl;
00079   cout << "Strategy adopted by FastJet was "<<
00080        clust_seq.strategy_string()<<endl<<endl;
00081 
00082   // extract the inclusive jets with pt > 5 GeV
00083   double ptmin = 5.0;
00084   vector<fastjet::PseudoJet> inclusive_jets = clust_seq.inclusive_jets(ptmin);
00085 
00086   // print them out
00087   cout << "Printing inclusive jets with pt > "<< ptmin<<" GeV\n";
00088   cout << "---------------------------------------\n";
00089   print_jets(clust_seq, inclusive_jets);
00090   cout << endl;
00091 
00092   // extract the exclusive jets with dcut = 25 GeV^2 
00093   double dcut = 25.0;
00094   vector<fastjet::PseudoJet> exclusive_jets = clust_seq.exclusive_jets(dcut);
00095 
00096   // print them out
00097   cout << "Printing exclusive jets with dcut = "<< dcut<<" GeV^2\n";
00098   cout << "--------------------------------------------\n";
00099   print_jets(clust_seq, exclusive_jets);
00100 
00101 
00102 }

void print_jets ( const fastjet::ClusterSequence ,
const vector< fastjet::PseudoJet > &   
)

a function that pretty prints a list of jets

Definition at line 107 of file fastjet_example.cc.

References fastjet::ClusterSequence::constituents(), and fastjet::sorted_by_pt().

00108                                                         {
00109 
00110   // sort jets into increasing pt
00111   vector<fastjet::PseudoJet> sorted_jets = sorted_by_pt(jets);  
00112 
00113   // label the columns
00114   printf("%5s %15s %15s %15s %15s\n","jet #", "rapidity", 
00115          "phi", "pt", "n constituents");
00116   
00117   // print out the details for each jet
00118   for (unsigned int i = 0; i < sorted_jets.size(); i++) {
00119     int n_constituents = clust_seq.constituents(sorted_jets[i]).size();
00120     printf("%5u %15.8f %15.8f %15.8f %8u\n",
00121            i, sorted_jets[i].rap(), sorted_jets[i].phi(),
00122            sorted_jets[i].perp(), n_constituents);
00123   }
00124 
00125 }


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