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G4DNARevertProbability.hh
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26 /*
27  * G4DNARevertFunction.hh
28  *
29  * Created on: Aug 25, 2015
30  * Author: mkaramit
31  */
32 
33 #ifndef SOURCE_PROCESSES_ELECTROMAGNETIC_DNA_UTILS_INCLUDE_G4DNAREVERTPROBABILITY_HH_
34 #define SOURCE_PROCESSES_ELECTROMAGNETIC_DNA_UTILS_INCLUDE_G4DNAREVERTPROBABILITY_HH_
35 
36 #include <functional>
37 
38 //------------------------------------------------------------------------------
39 // *****************************************************
40 // Revert a probability by binary search
41 // *****************************************************
42 
44 {
45 public:
46  double fXmax;
47  double fXmin;
48  double fXmaxDef;
49  double fXminDef;
52 
53  G4DNARevertProbability(double toleranceY) :
54  fToleranceProba(toleranceY)
55  {
56  fXmax = 0.;
57  fXmin = 0.;
58  fXminDef = 0.;
59  fXmaxDef = 0.;
61  }
62 
63  G4DNARevertProbability(double xmin, double xmax, double toleranceY) :
64  fXmax(xmax), fXmin(xmin), fToleranceProba(toleranceY)
65  {
66  if(fXmax < fXmin)
67  {
68  double tmp = fXmin;
69  fXmin = fXmax;
70  fXmax = tmp;
71  }
72 
73  fXminDef = fXmin;
74  fXmaxDef = fXmax;
76  }
77 
78  void Reset()
79  {
80  fXmin = fXminDef;
81  fXmax = fXmaxDef;
82  }
83 
84  void SetBoundaries(double xmin, double xmax)
85  {
86  fXmax = xmax;
87  fXmin = xmin;
88  if(fXmax < fXmin)
89  {
90  double tmp = fXmin;
91  fXmin = fXmax;
92  fXmax = tmp;
93  }
94 
95  fXminDef = fXmin;
96  fXmaxDef = fXmax;
97  }
98 
99  void SetTolerance(double toleranceY)
100  {
101  fToleranceProba = toleranceY;
102  }
103 
104  bool Propose(double proposedXValue,
105  double proposedProba,
106  double nextProba,
107  double& returnedValue)
108  {
109  bool returnFlag = false;
110 
111  if(proposedProba < nextProba - fToleranceProba) // proba trop petite ==> augmente
112  {
113  if(fIncreasingCumulativeFunction > 0) // croissant
114  {
115  if(proposedXValue > fXmin) fXmin = proposedXValue;
116  }
117  else if(fIncreasingCumulativeFunction < 0) // decroissant
118  {
119  if(proposedXValue < fXmax) fXmax = proposedXValue;
120  }
121 
122  returnedValue = (fXmax + fXmin) / 2.;
123  returnFlag = false;
124  }
125  else if(proposedProba > nextProba + fToleranceProba) // proba trop grande
126  {
128  {
129  if(proposedXValue < fXmax)
130  {
131  fXmax = proposedXValue;
132  }
133  }
134  else if(fIncreasingCumulativeFunction < 0)
135  {
136  if(proposedXValue > fXmin)
137  {
138  fXmin = proposedXValue;
139  }
140  }
141 
142  returnedValue = (fXmax + fXmin) / 2.;
143  returnFlag = false;
144  }
145  else
146  {
147  // Assuming search for next proba is increasing
149  {
150  fXmin = fXminDef;
151  fXmax = proposedXValue;
152  }
153  else if(fIncreasingCumulativeFunction > 0)
154  {
155  fXmin = proposedXValue;
156  fXmax = fXmaxDef;
157  }
158  returnFlag = true;
159  }
160 
161  return returnFlag;
162  }
163 
164  //**********************************
165  // *** REVERT THE FUNCTION "FUNCT"
166  // *********************************
167 
168  double Revert(double probaForSearchedTime,
169  std::function<double(double)>& funct)
170  {
171  Reset();
172  bool notFound = true;
173  double proposedX;
174  double x = fXmax;
175 
176  fIncreasingCumulativeFunction = (funct(fXmax) - funct(fXmin))
177  / (fXmax - fXmin);
178 
179  while(notFound)
180  {
181  double newProba = funct(x);
182 
183  if(Propose(x, newProba, probaForSearchedTime, proposedX))
184  {
185  notFound = false;
186  }
187  else
188  {
189  if(x == proposedX)
190  {
191  return x;
192 // G4cout << "BREAK : x= " << x << G4endl;
193 // G4cout << "nextProba= " << probaForSearchedTime << G4endl;
194 // G4cout << "newProba= " << newProba << G4endl;
195 // abort();
196  }
197  x = proposedX;
198  }
199  }
200  return x;
201  }
202 };
203 #endif /* SOURCE_PROCESSES_ELECTROMAGNETIC_DNA_UTILS_INCLUDE_G4DNAREVERTPROBABILITY_HH_ */