| Geant4 Cross Reference |
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25 //
26
27 #include "G4AdjointInterpolator.hh"
28
29 G4ThreadLocal G4AdjointInterpolator* G4AdjointInterpolator::fInstance = nullptr;
30
31 ///////////////////////////////////////////////////////
32 G4AdjointInterpolator* G4AdjointInterpolator::GetAdjointInterpolator()
33 {
34 return GetInstance();
35 }
36
37 ///////////////////////////////////////////////////////
38 G4AdjointInterpolator* G4AdjointInterpolator::GetInstance()
39 {
40 if(!fInstance)
41 {
42 fInstance = new G4AdjointInterpolator;
43 }
44 return fInstance;
45 }
46
47 ///////////////////////////////////////////////////////
48 G4AdjointInterpolator::G4AdjointInterpolator() {}
49
50 ///////////////////////////////////////////////////////
51 G4AdjointInterpolator::~G4AdjointInterpolator() {}
52
53 ///////////////////////////////////////////////////////
54 G4double G4AdjointInterpolator::LinearInterpolation(G4double& x, G4double& x1,
55 G4double& x2, G4double& y1,
56 G4double& y2)
57 {
58 G4double res = y1 + (x - x1) * (y2 - y1) / (x2 - x1);
59 return res;
60 }
61
62 ///////////////////////////////////////////////////////
63 G4double G4AdjointInterpolator::LogarithmicInterpolation(
64 G4double& x, G4double& x1, G4double& x2, G4double& y1, G4double& y2)
65 {
66 if(y1 <= 0. || y2 <= 0. || x1 <= 0.)
67 return LinearInterpolation(x, x1, x2, y1, y2);
68 G4double B = std::log(y2 / y1) / std::log(x2 / x1);
69 G4double A = y1 / std::pow(x1, B);
70 G4double res = A * std::pow(x, B);
71 return res;
72 }
73
74 ///////////////////////////////////////////////////////
75 G4double G4AdjointInterpolator::ExponentialInterpolation(
76 G4double& x, G4double& x1, G4double& x2, G4double& y1, G4double& y2)
77 {
78 G4double B = (std::log(y2) - std::log(y1)) / (x2 - x1);
79 G4double A = y1 * std::exp(-B * x1);
80 G4double res = A * std::exp(B * x);
81 return res;
82 }
83
84 ///////////////////////////////////////////////////////
85 G4double G4AdjointInterpolator::Interpolation(G4double& x, G4double& x1,
86 G4double& x2, G4double& y1,
87 G4double& y2,
88 const G4String& InterPolMethod)
89 {
90 if(InterPolMethod == "Log")
91 {
92 return LogarithmicInterpolation(x, x1, x2, y1, y2);
93 }
94 else if(InterPolMethod == "Lin")
95 {
96 return LinearInterpolation(x, x1, x2, y1, y2);
97 }
98 else if(InterPolMethod == "Exp")
99 {
100 return ExponentialInterpolation(x, x1, x2, y1, y2);
101 }
102 else
103 {
104 G4ExceptionDescription ed;
105 ed << "The interpolation method that you invoked does not exist!\n";
106 G4Exception("G4AdjointInterpolator::Interpolation", "adoint001",
107 FatalException, ed);
108 return 0.;
109 }
110 }
111
112 ///////////////////////////////////////////////////////
113 // only valid if x_vec is monotically increasing
114 std::size_t G4AdjointInterpolator::FindPosition(G4double& x,
115 std::vector<G4double>& x_vec, std::size_t,
116 std::size_t)
117 {
118 // most rapid method could be used probably
119
120 std::size_t ndim = x_vec.size();
121 std::size_t ind1 = 0;
122 std::size_t ind2 = ndim - 1;
123
124 if(ndim > 1)
125 {
126 if(x_vec[0] < x_vec[1])
127 { // increasing
128 do
129 {
130 std::size_t midBin = (ind1 + ind2) / 2;
131 if(x < x_vec[midBin])
132 ind2 = midBin;
133 else
134 ind1 = midBin;
135 } while(ind2 - ind1 > 1);
136 }
137 else
138 {
139 do
140 {
141 std::size_t midBin = (ind1 + ind2) / 2;
142 if(x < x_vec[midBin])
143 ind1 = midBin;
144 else
145 ind2 = midBin;
146 } while(ind2 - ind1 > 1);
147 }
148 }
149
150 return ind1;
151 }
152
153 ///////////////////////////////////////////////////////
154 // only valid if x_vec is monotically increasing
155 std::size_t G4AdjointInterpolator::FindPositionForLogVector(
156 G4double& log_x, std::vector<G4double>& log_x_vec)
157 {
158 // most rapid method could be used probably
159 return FindPosition(log_x, log_x_vec);
160 }
161
162 ///////////////////////////////////////////////////////
163 G4double G4AdjointInterpolator::Interpolate(G4double& x,
164 std::vector<G4double>& x_vec,
165 std::vector<G4double>& y_vec,
166 const G4String& InterPolMethod)
167 {
168 std::size_t i = FindPosition(x, x_vec);
169 return Interpolation(x, x_vec[i], x_vec[i + 1], y_vec[i], y_vec[i + 1],
170 InterPolMethod);
171 }
172
173 ///////////////////////////////////////////////////////
174 G4double G4AdjointInterpolator::InterpolateWithIndexVector(
175 G4double& x, std::vector<G4double>& x_vec, std::vector<G4double>& y_vec,
176 std::vector<std::size_t>& index_vec, G4double x0,
177 G4double dx) // only linear interpolation possible
178 {
179 std::size_t ind = 0;
180 if(x > x0)
181 ind = G4int((x - x0) / dx);
182 if(ind >= index_vec.size() - 1)
183 ind = index_vec.size() - 2;
184 std::size_t ind1 = index_vec[ind];
185 std::size_t ind2 = index_vec[ind + 1];
186 if(ind1 > ind2)
187 {
188 std::size_t ind11 = ind1;
189 ind1 = ind2;
190 ind2 = ind11;
191 }
192 ind = FindPosition(x, x_vec, ind1, ind2);
193 return Interpolation(x, x_vec[ind], x_vec[ind + 1], y_vec[ind],
194 y_vec[ind + 1], "Lin");
195 }
196
197 ///////////////////////////////////////////////////////
198 G4double G4AdjointInterpolator::InterpolateForLogVector(
199 G4double& log_x, std::vector<G4double>& log_x_vec,
200 std::vector<G4double>& log_y_vec)
201 {
202 std::size_t i = FindPositionForLogVector(log_x, log_x_vec);
203
204 G4double log_y = LinearInterpolation(log_x, log_x_vec[i], log_x_vec[i + 1],
205 log_y_vec[i], log_y_vec[i + 1]);
206 return log_y;
207 }
208