[1] | 1 | //STARTHEADER |
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| 2 | // $Id: GhostedAreaSpec.hh 2728 2011-11-20 14:18:59Z salam $ |
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| 3 | // |
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| 4 | // Copyright (c) 2005-2011, Matteo Cacciari, Gavin P. Salam and Gregory Soyez |
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| 5 | // |
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| 6 | //---------------------------------------------------------------------- |
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| 7 | // This file is part of FastJet. |
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| 8 | // |
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| 9 | // FastJet is free software; you can redistribute it and/or modify |
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| 10 | // it under the terms of the GNU General Public License as published by |
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| 11 | // the Free Software Foundation; either version 2 of the License, or |
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| 12 | // (at your option) any later version. |
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| 13 | // |
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| 14 | // The algorithms that underlie FastJet have required considerable |
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| 15 | // development and are described in hep-ph/0512210. If you use |
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| 16 | // FastJet as part of work towards a scientific publication, please |
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| 17 | // include a citation to the FastJet paper. |
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| 18 | // |
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| 19 | // FastJet is distributed in the hope that it will be useful, |
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| 20 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 21 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 22 | // GNU General Public License for more details. |
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| 23 | // |
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| 24 | // You should have received a copy of the GNU General Public License |
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| 25 | // along with FastJet. If not, see <http://www.gnu.org/licenses/>. |
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| 26 | //---------------------------------------------------------------------- |
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| 27 | //ENDHEADER |
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| 28 | |
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| 29 | |
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| 30 | #ifndef __FASTJET_GHOSTEDAREASPEC_HH__ |
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| 31 | #define __FASTJET_GHOSTEDAREASPEC_HH__ |
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| 32 | |
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| 33 | #include<vector> |
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| 34 | #include<string> |
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| 35 | #include "fastjet/PseudoJet.hh" |
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| 36 | #include "fastjet/internal/BasicRandom.hh" |
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| 37 | #include "fastjet/Selector.hh" |
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| 38 | #include "fastjet/LimitedWarning.hh" |
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| 39 | |
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| 40 | // |
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| 41 | #define STATIC_GENERATOR 1 |
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| 42 | |
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| 43 | FASTJET_BEGIN_NAMESPACE // defined in fastjet/internal/base.hh |
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| 44 | |
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| 45 | /// namespace to hold default parameters for the active area spec |
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| 46 | namespace gas { |
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| 47 | const double def_ghost_maxrap = 6.0; |
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| 48 | const int def_repeat = 1; |
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| 49 | const double def_ghost_area = 0.01; |
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| 50 | const double def_grid_scatter = 1.0; |
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| 51 | const double def_pt_scatter = 0.1; |
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| 52 | const double def_mean_ghost_pt = 1e-100; |
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| 53 | } |
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| 54 | |
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| 55 | //---------------------------------------------------------------------- |
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| 56 | /// @ingroup area_classes |
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| 57 | /// \class GhostedAreaSpec |
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| 58 | /// Parameters to configure the computation of jet areas using ghosts |
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| 59 | /// |
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| 60 | /// Class that defines the parameters that go into the measurement |
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| 61 | /// of active jet areas. |
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| 62 | class GhostedAreaSpec { |
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| 63 | public: |
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| 64 | /// default constructor |
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| 65 | GhostedAreaSpec(): _ghost_maxrap (gas::def_ghost_maxrap), |
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| 66 | _ghost_rap_offset(0.0), |
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| 67 | _repeat (gas::def_repeat), |
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| 68 | _ghost_area (gas::def_ghost_area), |
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| 69 | _grid_scatter (gas::def_grid_scatter), |
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| 70 | _pt_scatter (gas::def_pt_scatter), |
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| 71 | _mean_ghost_pt(gas::def_mean_ghost_pt), |
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| 72 | _fj2_placement(false) {_initialize();} |
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| 73 | |
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| 74 | /// explicit constructor |
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| 75 | explicit GhostedAreaSpec(double ghost_maxrap_in, |
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| 76 | int repeat_in = gas::def_repeat, |
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| 77 | double ghost_area_in = gas::def_ghost_area, |
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| 78 | double grid_scatter_in = gas::def_grid_scatter, |
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| 79 | double pt_scatter_in = gas::def_pt_scatter, |
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| 80 | double mean_ghost_pt_in = gas::def_mean_ghost_pt |
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| 81 | ): |
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| 82 | _ghost_maxrap(ghost_maxrap_in), |
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| 83 | _ghost_rap_offset(0.0), |
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| 84 | _repeat(repeat_in), |
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| 85 | _ghost_area(ghost_area_in), |
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| 86 | _grid_scatter(grid_scatter_in), |
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| 87 | _pt_scatter(pt_scatter_in), |
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| 88 | _mean_ghost_pt(mean_ghost_pt_in), |
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| 89 | _fj2_placement(false) {_initialize();} |
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| 90 | |
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| 91 | /// explicit constructor |
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| 92 | explicit GhostedAreaSpec(double ghost_minrap_in, |
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| 93 | double ghost_maxrap_in, |
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| 94 | int repeat_in = gas::def_repeat, |
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| 95 | double ghost_area_in = gas::def_ghost_area, |
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| 96 | double grid_scatter_in = gas::def_grid_scatter, |
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| 97 | double pt_scatter_in = gas::def_pt_scatter, |
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| 98 | double mean_ghost_pt_in = gas::def_mean_ghost_pt |
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| 99 | ): |
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| 100 | _ghost_maxrap (0.5*(ghost_maxrap_in - ghost_minrap_in)), |
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| 101 | _ghost_rap_offset(0.5*(ghost_maxrap_in + ghost_minrap_in)), |
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| 102 | _repeat(repeat_in), |
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| 103 | _ghost_area(ghost_area_in), |
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| 104 | _grid_scatter(grid_scatter_in), |
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| 105 | _pt_scatter(pt_scatter_in), |
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| 106 | _mean_ghost_pt(mean_ghost_pt_in), |
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| 107 | _fj2_placement(false) {_initialize();} |
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| 108 | |
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| 109 | |
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| 110 | /// constructor based on a Selector |
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| 111 | explicit GhostedAreaSpec(const Selector & selector, |
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| 112 | int repeat_in = gas::def_repeat, |
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| 113 | double ghost_area_in = gas::def_ghost_area, |
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| 114 | double grid_scatter_in = gas::def_grid_scatter, |
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| 115 | double pt_scatter_in = gas::def_pt_scatter, |
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| 116 | double mean_ghost_pt_in = gas::def_mean_ghost_pt |
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| 117 | ); |
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| 118 | |
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| 119 | |
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| 120 | /// does the initialization of actual ghost parameters |
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| 121 | void _initialize(); |
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| 122 | |
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| 123 | // for accessing values set by the user |
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| 124 | inline double ghost_etamax () const {return _ghost_maxrap;} |
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| 125 | inline double ghost_maxrap () const {return _ghost_maxrap;} |
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| 126 | inline double ghost_area () const {return _ghost_area ;} |
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| 127 | inline double grid_scatter () const {return _grid_scatter;} |
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| 128 | inline double pt_scatter () const {return _pt_scatter ;} |
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| 129 | inline double mean_ghost_pt() const {return _mean_ghost_pt ;} |
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| 130 | inline int repeat () const {return _repeat ;} |
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| 131 | inline bool fj2_placement() const {return _fj2_placement;} |
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| 132 | |
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| 133 | inline double kt_scatter () const {return _pt_scatter ;} |
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| 134 | inline double mean_ghost_kt() const {return _mean_ghost_pt ;} |
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| 135 | |
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| 136 | // for accessing values |
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| 137 | inline double actual_ghost_area() const {return _actual_ghost_area;} |
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| 138 | inline int n_ghosts() const {return _n_ghosts;} |
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| 139 | |
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| 140 | // when explicitly modifying values, sometimes call the initializer |
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| 141 | inline void set_ghost_area (double val) {_ghost_area = val; _initialize();} |
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| 142 | inline void set_ghost_etamax (double val) {_ghost_maxrap = val; _initialize();} |
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| 143 | inline void set_ghost_maxrap (double val) {_ghost_maxrap = val; _initialize();} |
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| 144 | inline void set_grid_scatter (double val) {_grid_scatter = val; } |
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| 145 | inline void set_pt_scatter (double val) {_pt_scatter = val; } |
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| 146 | inline void set_mean_ghost_pt(double val) {_mean_ghost_pt = val; } |
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| 147 | inline void set_repeat (int val) {_repeat = val; } |
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| 148 | |
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| 149 | inline void set_kt_scatter (double val) {_pt_scatter = val; } |
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| 150 | inline void set_mean_ghost_kt(double val) {_mean_ghost_pt = val; } |
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| 151 | |
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| 152 | /// if val is true, set ghost placement as it was in FastJet 2.X. The |
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| 153 | /// main differences between FJ2 and FJ3 ghost placement are |
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| 154 | /// |
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| 155 | /// - in FJ2 the rapidity spacing was |
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| 156 | /// ceil((maxrap-minrap)/sqrt(area)), while in FJ3 it is |
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| 157 | /// int((maxrap-minrap)/sqrt(area) + 0.5) [similarly for phi]. |
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| 158 | /// The FJ3 option offers more stability when trying to specify a |
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| 159 | /// spacing that exactly fits the extent. |
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| 160 | /// |
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| 161 | /// - in FJ2, the ghosts are placed at the corners of grid cells |
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| 162 | /// (i.e. extending up to maxrap), while in FJ3 they are placed at |
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| 163 | /// the centres of grid cells (i.e. extending roughly up to |
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| 164 | /// maxrap-sqrt(area)). The FJ2 behaviour effectively skews the |
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| 165 | /// total area coverage when maxrap is small, by an amount |
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| 166 | /// sqrt(area)/(2*maxrap). |
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| 167 | /// |
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| 168 | /// FJ2 placement is now deprecated. |
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| 169 | void set_fj2_placement(bool val); |
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| 170 | |
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| 171 | /// return nphi (ghosts layed out (-nrap, 0..nphi-1), (-nrap+1,0..nphi-1), |
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| 172 | /// ... (nrap,0..nphi-1) |
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| 173 | inline int nphi() const {return _nphi;} |
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| 174 | inline int nrap() const {return _nrap;} |
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| 175 | |
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| 176 | /// get all relevant information about the status of the |
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| 177 | /// random number generator, so that it can be reset subsequently |
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| 178 | /// with set_random_status. |
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| 179 | inline void get_random_status(std::vector<int> & __iseed) const { |
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| 180 | _random_generator.get_status(__iseed);} |
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| 181 | |
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| 182 | /// set the status of the random number generator, as obtained |
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| 183 | /// previously with get_random_status. Note that the random |
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| 184 | /// generator is a static member of the class, i.e. common to all |
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| 185 | /// instances of the class --- so if you modify the random for this |
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| 186 | /// instance, you modify it for all instances. |
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| 187 | inline void set_random_status(const std::vector<int> & __iseed) { |
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| 188 | _random_generator.set_status(__iseed);} |
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| 189 | |
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| 190 | inline void checkpoint_random() {get_random_status(_random_checkpoint);} |
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| 191 | inline void restore_checkpoint_random() {set_random_status(_random_checkpoint);} |
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| 192 | |
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| 193 | /// for a summary |
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| 194 | std::string description() const; |
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| 195 | |
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| 196 | /// push a set of ghost 4-momenta onto the back of the vector of |
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| 197 | /// PseudoJets |
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| 198 | void add_ghosts(std::vector<PseudoJet> & ) const; |
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| 199 | |
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| 200 | /// very deprecated public access to a random number |
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| 201 | /// from the internal generator |
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| 202 | inline double random_at_own_risk() const {return _our_rand();} |
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| 203 | /// very deprecated public access to the generator itself |
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| 204 | inline BasicRandom<double> & generator_at_own_risk() const { |
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| 205 | return _random_generator;} |
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| 206 | |
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| 207 | private: |
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| 208 | |
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| 209 | // quantities that determine nature and distribution of ghosts |
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| 210 | double _ghost_maxrap; |
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| 211 | double _ghost_rap_offset; |
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| 212 | int _repeat ; |
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| 213 | double _ghost_area ; |
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| 214 | double _grid_scatter; |
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| 215 | double _pt_scatter ; |
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| 216 | double _mean_ghost_pt; |
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| 217 | bool _fj2_placement; |
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| 218 | |
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| 219 | Selector _selector; |
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| 220 | |
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| 221 | // derived quantities |
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| 222 | double _actual_ghost_area, _dphi, _drap; |
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| 223 | int _n_ghosts, _nphi, _nrap; |
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| 224 | |
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| 225 | |
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| 226 | std::vector<int> _random_checkpoint; |
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| 227 | static BasicRandom<double> _random_generator; |
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| 228 | //mutable BasicRandom<double> _random_generator; |
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| 229 | |
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| 230 | static LimitedWarning _warn_fj2_placement_deprecated; |
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| 231 | |
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| 232 | inline double _our_rand() const {return _random_generator();} |
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| 233 | |
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| 234 | }; |
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| 235 | |
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| 236 | /// just provide a typedef for backwards compatibility with programs |
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| 237 | /// based on versions 2.0 and 2.1 of fastjet. Since there is no |
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| 238 | /// easy way of telling people this is deprecated at compile or run |
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| 239 | /// time, we should be careful before removing this in the future. |
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| 240 | typedef GhostedAreaSpec ActiveAreaSpec; |
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| 241 | |
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| 242 | |
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| 243 | FASTJET_END_NAMESPACE |
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| 244 | |
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| 245 | #endif // __FASTJET_GHOSTEDAREASPEC_HH__ |
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