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// ClusteringVetoPlugin Package
// Questions/Comments? liew@hep-th.phys.s.u-tokyo.ac.jp
// stoll@hep-th.phys.s.u-tokyo.ac.jp
//
// Copyright (c) 2014-2015
// Seng Pei Liew, Martin Stoll
//
// Example showing usage of ClusteringVetoPlugin
//
// Compile with "make example" and run with
// ./example < ../data/single-event.dat
//
// $Id: example.cc 788 2015-04-27 03:18:16Z martinstoll $
//----------------------------------------------------------------------
// This file is part of FastJet contrib.
//
// It is free software; you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2 of the License, or (at
// your option) any later version.
//
// It is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
// License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this code. If not, see <http://www.gnu.org/licenses/>.
//----------------------------------------------------------------------
#include <iostream>
#include <sstream>
#include <stdio.h>
#include "fastjet/PseudoJet.hh"
#include <sstream>
#include "ClusteringVetoPlugin.hh" // In external code, this should be fastjet/contrib/ClusteringVetoPlugin.hh
using namespace std;
using namespace fastjet;
using namespace contrib;
// forward declaration to make things clearer
void read_event(vector<PseudoJet> &event);
void print_jets(const vector<PseudoJet> &jets,
const ClusterSequence &clust_seq);
ClusteringVetoPlugin::VetoResult user_veto_function
(const PseudoJet& j1, const PseudoJet& j2);
//----------------------------------------------------------------------
int main(){
//----------------------------------------------------------
// read in input particles
vector<PseudoJet> event;
read_event(event);
cout << "# read an event with " << event.size() << " particles" << endl;
//----------------------------------------------------------
// illustrate how this ClusteringVetoPlugin contrib works
// basic Cambridge-Aachen-like mass-jump
//----------------------------------------------------------
{
// clustering parameters
double mu(30.), theta(0.7), max_r(1.0), ptmin(5.);
ClusteringVetoPlugin mj_plugin(mu, theta, max_r, ClusteringVetoPlugin::CALIKE);
JetDefinition jet_def(&mj_plugin);
ClusterSequence clust_seq(event, jet_def);
// print setup
cout << endl << "Run " << jet_def.description() << endl;
// get inclusive jets and print
vector<PseudoJet> jets = sorted_by_pt(clust_seq.inclusive_jets(ptmin));
cout << "Inclusive jets with pT > " << ptmin << " GeV" << endl;
print_jets(jets, clust_seq);
}
//----------------------------------------------------------
// kT-like and anti-kT-like
//----------------------------------------------------------
{
// clustering parameters
double mu(30.), theta(0.7), max_r(1.0), ptmin(5.);
// kT
ClusteringVetoPlugin mj_plugin_kt(mu, theta, max_r, ClusteringVetoPlugin::KTLIKE);
JetDefinition jet_def_kt(&mj_plugin_kt);
ClusterSequence clust_seq_kt(event, jet_def_kt);
cout << endl << "Run " << jet_def_kt.description() << endl;
vector<PseudoJet> jets_kt =
sorted_by_pt(clust_seq_kt.inclusive_jets(ptmin));
cout << "Inclusive jets with pT > " << ptmin << " GeV" << endl
<< " number of jets: " << jets_kt.size() << endl;
// anti-kT
ClusteringVetoPlugin mj_plugin_akt(mu, theta, max_r, ClusteringVetoPlugin::AKTLIKE);
JetDefinition jet_def_akt(&mj_plugin_akt);
ClusterSequence clust_seq_akt(event, jet_def_akt);
cout << endl << "Run " << jet_def_akt.description() << endl;
vector<PseudoJet> jets_akt =
sorted_by_pt(clust_seq_akt.inclusive_jets(ptmin));
cout << "Inclusive jets with pT > " << ptmin << " GeV" << endl
<< " number of jets: " << jets_akt.size() << endl;
}
//----------------------------------------------------------
// Cambridge-Aachen-like with user-defined veto function
//----------------------------------------------------------
{
// clustering parameters
double mu(30.), theta(0.7), max_r(1.0), ptmin(5.);
ClusteringVetoPlugin mj_plugin(mu, theta, max_r, ClusteringVetoPlugin::CALIKE);
// set veto function, renders mu and theta irrelevant
mj_plugin.set_veto_function(user_veto_function);
JetDefinition jet_def(&mj_plugin);
ClusterSequence clust_seq(event, jet_def);
// print setup
cout << endl << "Run " << jet_def.description() << endl;
// get inclusive jets and print
vector<PseudoJet> jets = sorted_by_pt(clust_seq.inclusive_jets(ptmin));
cout << "Inclusive jets with pT > " << ptmin << " GeV" << endl;
print_jets(jets, clust_seq);
}
return 0;
}
// read in input particles
void read_event(vector<PseudoJet> &event){
string line;
while (getline(cin, line)) {
istringstream linestream(line);
// take substrings to avoid problems when there are extra "pollution"
// characters (e.g. line-feed).
if (line.substr(0,4) == "#END") {return;}
if (line.substr(0,1) == "#") {continue;}
double px,py,pz,E;
linestream >> px >> py >> pz >> E;
PseudoJet particle(px,py,pz,E);
// push event onto back of full_event vector
event.push_back(particle);
}
}
// prints a vector of jets
void print_jets(const vector<PseudoJet> &jets,
const ClusterSequence &clust_seq){
// columns labels
printf("%5s %10s %10s %10s %10s %10s\n",
"jet #", "pt", "rap", "phi", "m", "last d_ij");
// print out the jets
for (unsigned i=0; i<jets.size(); ++i) {
printf("%5u %10.3f %10.3f %10.3f %10.3f %10.3f\n",
i, jets[i].pt(), jets[i].rap(), jets[i].phi(), jets[i].m(),
clust_seq.exclusive_subdmerge ( jets[i], 1 ));
}
}
// example of user-defined veto function
ClusteringVetoPlugin::VetoResult user_veto_function
( const PseudoJet& j1, const PseudoJet& j2 ) {
// DeltaR instead of jet-mass (mu) threshold
if ( j1.delta_R(j2) < 0.3 )
return ClusteringVetoPlugin::CLUSTER;
// mass-jump veto with theta=0.5
else if ( 0.5 * (j1+j2).m() > max( j1.m(), j2.m() ) )
return ClusteringVetoPlugin::VETO;
// no veto, but algorithm may need to check active-passive veto
return ClusteringVetoPlugin::NOVETO;
}

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