1 | // -*- C++ -*- |
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2 | /////////////////////////////////////////////////////////////////////////////// |
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3 | // File: area.h // |
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4 | // Description: header file for the computation of jet area // |
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5 | // This file is part of the SISCone project. // |
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6 | // For more details, see http://projects.hepforge.org/siscone // |
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7 | // // |
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8 | // Copyright (c) 2006 Gavin Salam and Gregory Soyez // |
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9 | // // |
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10 | // This program is free software; you can redistribute it and/or modify // |
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11 | // it under the terms of the GNU General Public License as published by // |
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12 | // the Free Software Foundation; either version 2 of the License, or // |
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13 | // (at your option) any later version. // |
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14 | // // |
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15 | // This program is distributed in the hope that it will be useful, // |
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16 | // but WITHOUT ANY WARRANTY; without even the implied warranty of // |
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17 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // |
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18 | // GNU General Public License for more details. // |
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19 | // // |
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20 | // You should have received a copy of the GNU General Public License // |
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21 | // along with this program; if not, write to the Free Software // |
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22 | // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA // |
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23 | // // |
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24 | // $Revision:: 859 $// |
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25 | // $Date:: 2012-11-28 02:49:23 +0100 (Wed, 28 Nov 2012) $// |
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26 | /////////////////////////////////////////////////////////////////////////////// |
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27 | |
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28 | #include "area.h" |
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29 | #include "momentum.h" |
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30 | #include <stdlib.h> |
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31 | #include <iostream> |
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32 | |
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33 | namespace siscone{ |
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34 | using namespace std; |
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35 | |
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36 | /******************************************************* |
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37 | * Cjet_area implementation * |
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38 | * real Jet information, including its area(s) * |
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39 | * * |
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40 | * This class contains information for one single jet. * |
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41 | * That is, first, its momentum carrying information * |
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42 | * about its centre and pT, and second, its particle * |
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43 | * contents (from CJeT). * |
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44 | * Compared to the Cjet class, it also includes the * |
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45 | * passive and active areas of the jet computed using * |
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46 | * the Carea class. * |
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47 | *******************************************************/ |
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48 | |
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49 | // default ctor |
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50 | //-------------- |
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51 | Cjet_area::Cjet_area(){ |
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52 | active_area = passive_area = 0.0; |
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53 | } |
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54 | |
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55 | // jet-initiated ctor |
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56 | //------------------- |
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57 | Cjet_area::Cjet_area(Cjet &j){ |
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58 | v = j.v; |
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59 | n = j.n; |
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60 | contents = j.contents; |
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61 | |
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62 | pass = j.pass; |
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63 | |
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64 | pt_tilde = j.pt_tilde; |
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65 | sm_var2 = j.sm_var2; |
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66 | |
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67 | active_area = passive_area = 0.0; |
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68 | } |
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69 | |
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70 | // default dtor |
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71 | //-------------- |
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72 | Cjet_area::~Cjet_area(){ |
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73 | |
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74 | } |
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75 | |
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76 | |
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77 | /****************************************************************** |
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78 | * Csiscone_area implementation * |
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79 | * class for the computation of jet areas. * |
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80 | * * |
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81 | * This is the class user should use whenever you want to compute * |
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82 | * the jet area (passive and active). * |
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83 | * It uses the SISCone algorithm to perform the jet analysis. * |
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84 | ******************************************************************/ |
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85 | |
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86 | // default ctor |
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87 | //------------- |
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88 | Carea::Carea(){ |
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89 | grid_size = 60; // 3600 particles added |
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90 | grid_eta_max = 6.0; // maybe having twice more points in eta than in phi should be nice |
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91 | grid_shift = 0.5; // 50% "shacking" |
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92 | |
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93 | pt_soft = 1e-100; |
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94 | pt_shift = 0.05; |
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95 | pt_soft_min = 1e-90; |
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96 | } |
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97 | |
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98 | // default dtor |
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99 | //------------- |
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100 | Carea::~Carea(){ |
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101 | |
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102 | } |
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103 | |
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104 | /* |
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105 | * compute the jet areas from a given particle set. |
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106 | * The parameters of this method are the ones which control the jet clustering alghorithm. |
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107 | * Note that the pt_min is not allowed here soince the jet-area determination involves soft |
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108 | * particles/jets and thus is used internally. |
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109 | * - _particles list of particles |
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110 | * - _radius cone radius |
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111 | * - _f shared energy threshold for splitting&merging |
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112 | * - _n_pass_max maximum number of passes (0=full search, the default) |
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113 | * - _split_merge_scale the scale choice for the split-merge procedure |
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114 | * NOTE: SM_pt leads to IR unsafety for some events with momentum conservation. |
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115 | * SM_Et is IR safe but not boost invariant and not implemented(!) |
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116 | * SM_mt is IR safe for hadronic events, but not for decays of two |
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117 | * back-to-back particles of identical mass |
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118 | * SM_pttilde |
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119 | * is always IR safe, and also boost invariant (default) |
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120 | * - _hard_only when this is set on, only hard jets are computed |
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121 | * and not the purely ghosted jets (default: false) |
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122 | * return the jets together with their areas |
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123 | * The return value is the number of jets (including pure-ghost ones if they are included) |
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124 | ********************************************************************************************/ |
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125 | int Carea::compute_areas(std::vector<Cmomentum> &_particles, double _radius, double _f, |
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126 | int _n_pass_max, Esplit_merge_scale _split_merge_scale, |
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127 | bool _hard_only){ |
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128 | |
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129 | vector<Cmomentum> all_particles; |
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130 | |
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131 | // put "hardest cut-off" if needed |
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132 | // this avoids computation of ghosted jets when not required and |
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133 | // significantly shortens the SM. |
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134 | if (_hard_only){ |
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135 | SM_var2_hardest_cut_off = pt_soft_min*pt_soft_min; |
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136 | } |
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137 | |
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138 | // clear potential previous runs |
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139 | jet_areas.clear(); |
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140 | |
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141 | // put initial set of particles in the list |
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142 | int n_hard = _particles.size(); |
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143 | all_particles = _particles; |
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144 | |
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145 | // build the set of ghost particles and add them to the particle list |
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146 | int i,j; |
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147 | double eta_g,phi_g,pt_g; |
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148 | |
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149 | for (i=0;i<grid_size;i++){ |
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150 | for (j=0;j<grid_size;j++){ |
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151 | eta_g = grid_eta_max*(-1.0+2.0*(i+0.5+grid_shift*(-1.0+2.0*(rand()/(RAND_MAX+1.0))))/grid_size); |
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152 | phi_g = M_PI *(-1.0+2.0*(j+0.5+grid_shift*(-1.0+2.0*(rand()/(RAND_MAX+1.0))))/grid_size); |
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153 | pt_g = pt_soft*(1.0+pt_shift*(-1.0+2.0*(rand()/(RAND_MAX+1.0)))); |
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154 | all_particles.push_back(Cmomentum(pt_g*cos(phi_g),pt_g*sin(phi_g),pt_g*sinh(eta_g),pt_g*cosh(eta_g))); |
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155 | } |
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156 | } |
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157 | |
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158 | // run clustering with all particles. |
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159 | // the split-merge here dynamically accounts for the purely soft jets. |
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160 | // we therefore end up with the active area for the jets |
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161 | int n_jets = compute_jets(all_particles, _radius, _f, _n_pass_max, 0.0, _split_merge_scale); |
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162 | |
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163 | // save jets in the Cjet_area structure |
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164 | // and determine their size |
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165 | // jet contents is ordered by increasing index of the initial |
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166 | // particles. Hence, we look for the first particle with index >= n_hard |
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167 | // and deduce the number of ghosts in the jet, hence the area. |
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168 | double area_factor = (2.0*grid_eta_max/grid_size)*(twopi/grid_size); |
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169 | |
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170 | for (i=0;i<(int) jets.size();i++){ |
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171 | jet_areas.push_back(jets[i]); |
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172 | j=0; |
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173 | while ((j<jets[i].n) && (jets[i].contents[j]<n_hard)) j++; |
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174 | jet_areas[i].active_area = (jets[i].n-j)*area_factor; |
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175 | } |
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176 | |
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177 | // determine passive jet area |
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178 | // for that onem we use the pt_min cut in order to remove purely |
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179 | // soft jets from the SM procedure |
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180 | recompute_jets(_f, pt_soft_min); |
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181 | |
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182 | // for the area computation, we assume the jete order is the same! |
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183 | for (i=0;i<(int) jets.size();i++){ |
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184 | j=0; |
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185 | while ((j<jets[i].n) && (jets[i].contents[j]<n_hard)) j++; |
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186 | jet_areas[i].passive_area = (jets[i].n-j)*area_factor; |
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187 | } |
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188 | |
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189 | // Note: |
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190 | // there surely remain purely soft je at the end |
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191 | // their active area is 0 by default (see ctor) |
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192 | |
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193 | jets.clear(); |
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194 | |
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195 | return n_jets; |
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196 | } |
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197 | |
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198 | /* |
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199 | * compute the passive jet areas from a given particle set. |
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200 | * The parameters of this method are the ones which control the jet clustering alghorithm. |
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201 | * Note that the pt_min is not allowed here soince the jet-area determination involves soft |
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202 | * particles/jets and thus is used internally. |
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203 | * - _particles list of particles |
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204 | * - _radius cone radius |
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205 | * - _f shared energy threshold for splitting&merging |
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206 | * - _n_pass_max maximum number of passes (0=full search, the default) |
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207 | * - _split_merge_scale the scale choice for the split-merge procedure |
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208 | * NOTE: SM_pt leads to IR unsafety for some events with momentum conservation. |
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209 | * SM_Et is IR safe but not boost invariant and not implemented(!) |
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210 | * SM_mt is IR safe for hadronic events, but not for decays of two |
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211 | * back-to-back particles of identical mass |
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212 | * SM_pttilde |
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213 | * is always IR safe, and also boost invariant (default) |
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214 | * return the jets together with their passive areas |
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215 | * The return value is the number of jets |
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216 | ********************************************************************************************/ |
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217 | int Carea::compute_passive_areas(std::vector<Cmomentum> &_particles, double _radius, double _f, |
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218 | int _n_pass_max, Esplit_merge_scale _split_merge_scale){ |
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219 | |
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220 | vector<Cmomentum> all_particles; |
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221 | |
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222 | // in the case of passive area, we do not need |
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223 | // to put the ghosts in the stable-cone search |
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224 | // (they do no influence the list of stable cones) |
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225 | // Here's how it goes... |
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226 | stable_cone_soft_pt2_cutoff = pt_soft_min*pt_soft_min; |
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227 | |
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228 | // clear potential previous runs |
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229 | jet_areas.clear(); |
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230 | |
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231 | // put initial set of particles in the list |
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232 | int n_hard = _particles.size(); |
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233 | all_particles = _particles; |
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234 | |
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235 | // build the set of ghost particles and add them to the particle list |
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236 | int i,j; |
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237 | double eta_g,phi_g,pt_g; |
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238 | |
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239 | for (i=0;i<grid_size;i++){ |
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240 | for (j=0;j<grid_size;j++){ |
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241 | eta_g = grid_eta_max*(-1.0+2.0*(i+0.5+grid_shift*(-1.0+2.0*(rand()/(RAND_MAX+1.0))))/grid_size); |
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242 | phi_g = M_PI *(-1.0+2.0*(j+0.5+grid_shift*(-1.0+2.0*(rand()/(RAND_MAX+1.0))))/grid_size); |
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243 | pt_g = pt_soft*(1.0+pt_shift*(-1.0+2.0*(rand()/(RAND_MAX+1.0)))); |
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244 | all_particles.push_back(Cmomentum(pt_g*cos(phi_g),pt_g*sin(phi_g),pt_g*sinh(eta_g),pt_g*cosh(eta_g))); |
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245 | } |
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246 | } |
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247 | |
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248 | // determine passive jet area |
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249 | // for that onem we use the pt_min cut in order to remove purely |
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250 | // soft jets from the SM procedure |
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251 | int n_jets = compute_jets(all_particles, _radius, _f, _n_pass_max, pt_soft_min, _split_merge_scale); |
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252 | |
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253 | // save jets in the Cjet_area structure |
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254 | // and determine their size |
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255 | // jet contents is ordered by increasing index of the initial |
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256 | // particles. Hence, we look for the first particle with index >= n_hard |
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257 | // and deduce the number of ghosts in the jet, hence the area. |
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258 | double area_factor = (2.0*grid_eta_max/grid_size)*(twopi/grid_size); |
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259 | for (i=0;i<(int) jets.size();i++){ |
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260 | j=0; |
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261 | while ((j<jets[i].n) && (jets[i].contents[j]<n_hard)) j++; |
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262 | jet_areas[i].passive_area = (jets[i].n-j)*area_factor; |
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263 | } |
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264 | |
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265 | jets.clear(); |
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266 | |
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267 | return n_jets; |
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268 | } |
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269 | |
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270 | /* |
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271 | * compute the active jet areas from a given particle set. |
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272 | * The parameters of this method are the ones which control the jet clustering alghorithm. |
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273 | * Note that the pt_min is not allowed here soince the jet-area determination involves soft |
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274 | * particles/jets and thus is used internally. |
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275 | * - _particles list of particles |
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276 | * - _radius cone radius |
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277 | * - _f shared energy threshold for splitting&merging |
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278 | * - _n_pass_max maximum number of passes (0=full search, the default) |
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279 | * - _split_merge_scale the scale choice for the split-merge procedure |
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280 | * NOTE: SM_pt leads to IR unsafety for some events with momentum conservation. |
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281 | * SM_Et is IR safe but not boost invariant and not implemented(!) |
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282 | * SM_mt is IR safe for hadronic events, but not for decays of two |
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283 | * back-to-back particles of identical mass |
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284 | * SM_pttilde |
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285 | * is always IR safe, and also boost invariant (default) |
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286 | * - _hard_only when this is set on, only hard jets are computed |
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287 | * and not the purely ghosted jets (default: false) |
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288 | * return the jets together with their active areas |
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289 | * The return value is the number of jets (including pure-ghost ones if they are included) |
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290 | ********************************************************************************************/ |
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291 | int Carea::compute_active_areas(std::vector<Cmomentum> &_particles, double _radius, double _f, |
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292 | int _n_pass_max, Esplit_merge_scale _split_merge_scale, |
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293 | bool _hard_only){ |
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294 | |
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295 | vector<Cmomentum> all_particles; |
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296 | |
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297 | // put "hardest cut-off" if needed |
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298 | // this avoids computation of ghosted jets when not required and |
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299 | // significantly shortens the SM. |
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300 | if (_hard_only){ |
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301 | SM_var2_hardest_cut_off = pt_soft_min*pt_soft_min; |
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302 | } |
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303 | |
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304 | // clear potential previous runs |
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305 | jet_areas.clear(); |
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306 | |
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307 | // put initial set of particles in the list |
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308 | int n_hard = _particles.size(); |
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309 | all_particles = _particles; |
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310 | |
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311 | // build the set of ghost particles and add them to the particle list |
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312 | int i,j; |
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313 | double eta_g,phi_g,pt_g; |
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314 | |
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315 | for (i=0;i<grid_size;i++){ |
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316 | for (j=0;j<grid_size;j++){ |
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317 | eta_g = grid_eta_max*(-1.0+2.0*(i+0.5+grid_shift*(-1.0+2.0*(rand()/(RAND_MAX+1.0))))/grid_size); |
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318 | phi_g = M_PI *(-1.0+2.0*(j+0.5+grid_shift*(-1.0+2.0*(rand()/(RAND_MAX+1.0))))/grid_size); |
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319 | pt_g = pt_soft*(1.0+pt_shift*(-1.0+2.0*(rand()/(RAND_MAX+1.0)))); |
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320 | all_particles.push_back(Cmomentum(pt_g*cos(phi_g),pt_g*sin(phi_g),pt_g*sinh(eta_g),pt_g*cosh(eta_g))); |
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321 | } |
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322 | } |
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323 | |
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324 | // run clustering with all particles. |
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325 | // the split-merge here dynamically accounts for the purely soft jets. |
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326 | // we therefore end up with the active area for the jets |
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327 | int n_jets = compute_jets(all_particles, _radius, _f, _n_pass_max, 0.0, _split_merge_scale); |
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328 | |
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329 | // save jets in the Cjet_area structure |
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330 | // and determine their size |
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331 | // jet contents is ordered by increasing index of the initial |
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332 | // particles. Hence, we look for the first particle with index >= n_hard |
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333 | // and deduce the number of ghosts in the jet, hence the area. |
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334 | double area_factor = (2.0*grid_eta_max/grid_size)*(twopi/grid_size); |
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335 | |
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336 | for (i=0;i<(int) jets.size();i++){ |
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337 | jet_areas.push_back(jets[i]); |
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338 | j=0; |
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339 | while ((j<jets[i].n) && (jets[i].contents[j]<n_hard)) j++; |
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340 | jet_areas[i].active_area = (jets[i].n-j)*area_factor; |
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341 | } |
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342 | |
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343 | jets.clear(); |
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344 | |
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345 | return n_jets; |
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346 | } |
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347 | |
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348 | } |
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