File: GeneralSampler.h

package info (click to toggle)
herwig%2B%2B 2.6.0-1
  • links: PTS, VCS
  • area: main
  • in suites: jessie, jessie-kfreebsd
  • size: 27,128 kB
  • ctags: 24,739
  • sloc: cpp: 188,949; fortran: 23,193; sh: 11,365; python: 5,069; ansic: 3,539; makefile: 1,865; perl: 2
file content (281 lines) | stat: -rw-r--r-- 6,538 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
// -*- C++ -*-
//
// GeneralSampler.h is a part of Herwig++ - A multi-purpose Monte Carlo event generator
// Copyright (C) 2002-2012 The Herwig Collaboration
//
// Herwig++ is licenced under version 2 of the GPL, see COPYING for details.
// Please respect the MCnet academic guidelines, see GUIDELINES for details.
//
#ifndef Herwig_GeneralSampler_H
#define Herwig_GeneralSampler_H
//
// This is the declaration of the GeneralSampler class.
//

#include "ThePEG/Handlers/SamplerBase.h"
#include "BinSampler.h"

namespace Herwig {

using namespace ThePEG;

/**
 * \ingroup Matchbox
 * \author Simon Platzer
 *
 * \brief A GeneralSampler class
 *
 * @see \ref GeneralSamplerInterfaces "The interfaces"
 * defined for GeneralSampler.
 */
class GeneralSampler: public SamplerBase {

public:

  /**
   * Exception thrown in case too many attempts to unweight an event.
   */
  struct MaxTryException : public ThePEG::Exception {};

  /** @name Standard constructors and destructors. */
  //@{
  /**
   * The default constructor.
   */
  GeneralSampler();

  /**
   * The destructor.
   */
  virtual ~GeneralSampler();
  //@}

public:

  /** @name Virtual functions from SamplerBase. */
  //@{
  /**
   * Initialize the the sampler, possibly doing presampling of the
   * phase space.
   */
  virtual void initialize();

  /**
   * Generarate a new phase space point and return a weight associated
   * with it. This weight should preferably be 1.
   */
  virtual double generate();

  /**
   * Reject the last chosen phase space point.
   */
  virtual void rejectLast();

  /**
   * If the sampler is able to sample several different functions
   * separately, this function should return the last chosen
   * function. This default version always returns 0.
   */
  virtual int lastBin() const { return lastSampler ? lastSampler->bin() : 0; }

  /**
   * Return the total integrated cross section determined from the
   * Monte Carlo sampling so far.
   */
  virtual CrossSection integratedXSec() const {
    currentCrossSections();
    return theIntegratedXSec * nanobarn;
  }

  /**
   * Return the error on the total integrated cross section determined
   * from the Monte Carlo sampling so far.
   */
  virtual CrossSection integratedXSecErr() const {
    currentCrossSections();
    return theIntegratedXSecErr * nanobarn;
  }

  /**
   * Return the overestimated integrated cross section.
   */
  virtual CrossSection maxXSec() const {
    currentCrossSections();
    return abs(theIntegratedXSec) * nanobarn;
  }

  /**
   * Return the sum of the weights returned by generate() so far (of
   * the events that were not rejeted).
   */
  virtual double sumWeights() const {
    return theSumWeights;
  }
  //@}

protected:

  /**
   * Calculate cross sections from samplers, assuming the start of a
   * new iteration.
   */
  void updateCrossSections(bool firstTime = false);

  /**
   * Calculate cross sections from samplers at current state.
   */
  void currentCrossSections() const;

public:

  /** @name Functions used by the persistent I/O system. */
  //@{
  /**
   * Function used to write out object persistently.
   * @param os the persistent output stream written to.
   */
  void persistentOutput(PersistentOStream & os) const;

  /**
   * Function used to read in object persistently.
   * @param is the persistent input stream read from.
   * @param version the version number of the object when written.
   */
  void persistentInput(PersistentIStream & is, int version);
  //@}

  /**
   * The standard Init function used to initialize the interfaces.
   * Called exactly once for each class by the class description system
   * before the main function starts or
   * when this class is dynamically loaded.
   */
  static void Init();

protected:

  /** @name Clone Methods. */
  //@{
  /**
   * Make a simple clone of this object.
   * @return a pointer to the new object.
   */
  virtual IBPtr clone() const;

  /** Make a clone of this object, possibly modifying the cloned object
   * to make it sane.
   * @return a pointer to the new object.
   */
  virtual IBPtr fullclone() const;
  //@}


// If needed, insert declarations of virtual function defined in the
// InterfacedBase class here (using ThePEG-interfaced-decl in Emacs).


protected:

  /**
   * Initialize this object. Called in the run phase just before
   * a run begins.
   */
  virtual void doinitrun();

  /**
   * Finalize this object. Called in the run phase just after a
   * run has ended. Used eg. to write out statistics.
   */
  virtual void dofinish();

  /**
   * Rebind pointer to other Interfaced objects. Called in the setup phase
   * after all objects used in an EventGenerator has been cloned so that
   * the pointers will refer to the cloned objects afterwards.
   * @param trans a TranslationMap relating the original objects to
   * their respective clones.
   * @throws RebindException if no cloned object was found for a given
   * pointer.
   */
  virtual void rebind(const TranslationMap & trans);

  /**
   * Return a vector of all pointers to Interfaced objects used in this
   * object.
   * @return a vector of pointers.
   */
  virtual IVector getReferences();

private:

  /**
   * The bin sampler to use.
   */
  Ptr<BinSampler>::ptr theBinSampler;

  /**
   * Whether or not additional information should be printed to cout.
   */
  bool theVerbose;

  /**
   * True, if subprocesses should be selected flat. This is a debug
   * flag, cross section information and distributions will not be
   * correct.
   */
  bool theFlatSubprocesses;

  /**
   * True, if we are generating events.
   */
  bool isSampling;

  /**
   * The selector map for the bin samplers.
   */
  map<double,Ptr<BinSampler>::ptr> samplers;

  /**
   * The last selected bin sampler.
   */
  Ptr<BinSampler>::tptr lastSampler;

  /**
   * The integrated cross section in nanobarn
   */
  mutable double theIntegratedXSec;

  /**
   * The integrated cross section error in nanobarn
   */
  mutable double theIntegratedXSecErr;

  /**
   * The sum of weights
   */
  double theSumWeights;

  /**
   * The sum of absolute cross section.
   */ 
  double norm;

  /**
   * Map samplers to events to be skipped owing to encounter of a new
   * maximum.
   */
  map<Ptr<BinSampler>::tptr,unsigned long> skipMap;

private:

  /**
   * The assignment operator is private and must never be called.
   * In fact, it should not even be implemented.
   */
  GeneralSampler & operator=(const GeneralSampler &);

};

}

#endif /* Herwig_GeneralSampler_H */