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