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26 /*
27 * File: G4FPYSamplingOps.hh
28 * Author: B. Wendt (wendbryc@isu.edu)
29 *
30 * Created on June 30, 2011, 11:10 AM
31 */
32
33 /* * * * * * * * * * * * * * * * References * * * * * * * * * * * * * * * *
34 * *
35 * 1. "Sampling ENDL Watt Fission Spectra, D. E. Cullen, LLNL, April, 2004 *
36 * *
37 * * * * * * * * * * * * * * * * References * * * * * * * * * * * * * * * */
38
39 #ifndef G4FPYSAMPLINGOPS_HH
40 #define G4FPYSAMPLINGOPS_HH
41
42 #include "G4FFGEnumerations.hh"
43 #include "G4ShiftedGaussian.hh"
44 #include "G4WattFissionSpectrumValues.hh"
45 #include "Randomize.hh"
46 #include "globals.hh"
47
48 /** G4FPYSamplingOps performs all the uniform and Gaussian distribution sampling
49 * operations
50 */
51 class G4FPYSamplingOps
52 {
53 public:
54 // Constructor definition
55 /** Default constructor
56 * - Usage: No arguments required
57 * - Notes:
58 */
59 G4FPYSamplingOps();
60 /** Overloaded constructor
61 * - Usage:
62 * - \p Verbosity: Verbosity level
63 * - Notes:
64 */
65 G4FPYSamplingOps(G4int Verbosity);
66
67 protected:
68 /** Initialize is a common function called by all constructors. */
69 void Initialize();
70
71 public:
72 // Functions
73 /** Returns an integer value taken from a Gaussian distribution.
74 * This overloaded version assumes that the range is not restricted to
75 * positive values only.
76 * - Usage:
77 * - \p Mean: Mean about which the Gaussian distribution will be
78 * sampled
79 * - \p StdDev: Standard deviation of the Gaussian distribution. 68.3%
80 * of the values will lie within the first standard deviation, 95.4%
81 * within the second standard deviation, etc...
82 * - Notes:
83 */
84 G4int G4SampleIntegerGaussian(G4double Mean, G4double StdDev);
85 /** Returns an integer value taken from a Gaussian distribution about
86 * \p Mean and with a standard deviation of \p StdDev.
87 * - Usage:
88 * - \p Mean: Mean about which the Gaussian distribution will be
89 * sampled
90 * - \p StdDev: Standard deviation of the Gaussian distribution. 68.3%
91 * of the values will lie within the first standard deviation, 95.4%
92 * within the second standard deviation, etc...
93 * - \p Range: \p POSITIVE or \p ALL
94 * - Notes:
95 */
96 G4int G4SampleIntegerGaussian(G4double Mean, G4double StdDev,
97 G4FFGEnumerations::GaussianRange Range);
98 /** Returns a double value taken from a Gaussian distribution about \p Mean
99 * and with a standard deviation of \p StdDev.
100 * - Usage:
101 * - \p Mean: Mean about which the Gaussian distribution will be
102 * sampled
103 * - \p StdDev: Standard deviation of the Gaussian distribution. 68.3%
104 * of the values will lie within the first standard deviation, 95.4%
105 * within the second standard deviation, etc...
106 * - Notes:
107 */
108 G4double G4SampleGaussian(G4double Mean, G4double StdDev);
109 /** Returns a double value taken from a Gaussian distribution about \p Mean
110 * and with a standard deviation of \p StdDev.
111 * - Usage:
112 * - \p Mean: Mean about which the Gaussian distribution will be
113 * sampled
114 * - \p StdDev: Standard deviation of the Gaussian distribution. 68.3%
115 * of the values will lie within the first standard deviation, 95.4%
116 * within the second standard deviation, etc...
117 * - \p Range: \p POSITIVE or \p ALL
118 * - Notes:
119 */
120 G4double G4SampleGaussian(G4double Mean, G4double StdDev,
121 G4FFGEnumerations::GaussianRange Range);
122 /** Returns a double value evenly distributed in the range (0, 1].
123 * - Usage: No arguments required
124 * - Notes:
125 */
126 G4double G4SampleUniform();
127 /** Returns a double value evenly distributed in the range
128 * (\p Lower, \p Upper].
129 * - Usage:
130 * - \p Lower: Lower bounds of the distribution
131 * - \p Upper: Upper bounds of the distribution
132 *
133 * - Notes:
134 */
135 G4double G4SampleUniform(G4double Lower, G4double Upper);
136 /** Samples the Watt fission spectrum for the selected isotope, using an
137 * algorithm adopted from Ref. 1
138 * - Usage:
139 * - \p WhatIsotope: The isotope that is to be sampled
140 * - \p WhatCause: The cause of the isotope to be sampled
141 * - \p WhatEnergy: The energy, in MeV of the incident particle
142 * - Notes:
143 * - All variables needed for this function are grouped together in
144 * WattConstants_.
145 * -
146 */
147 G4double G4SampleWatt(G4int WhatIsotope, G4FFGEnumerations::FissionCause WhatCause,
148 G4double WhatEnergy);
149 /** Sets the verbosity levels
150 * - Usage:
151 * - \p WhichVerbosity: Combination of levels
152 *
153 * - Notes:
154 * - \p SILENT: All verbose output is repressed
155 * - \p UPDATES: Only high-level internal changes are reported
156 * - \p DAUGHTER_INFO: Displays information about daughter product sampling
157 * - \p NEUTRON_INFO: Displays information about neutron sampling
158 * - \p GAMMA_INFO: Displays information about gamma sampling
159 * - \p ALPHA_INFO: Displays information about alpha sampling
160 * - \p MOMENTUM_INFO: Displays information about momentum balancing
161 * - \p EXTRAPOLATION_INTERPOLATION_INFO: Displays information about any data extrapolation
162 * or interpolation that occurs
163 * - \p DEBUG: Reports program flow as it steps through functions
164 * - \p PRINT_ALL: Displays any and all output
165 */
166 void G4SetVerbosity(G4int WhatVerbosity);
167
168 protected:
169 // Variables
170 // Class descriptor variables
171 /** Mean for sampling a Gaussian distribution */
172 G4double Mean_;
173 /** Standard deviation for sampling a GaussianDistribution */
174 G4double StdDev_;
175 /** Structure chain that contains the all the previous values used
176 * for sampling a Gaussian distribution
177 */
178 G4ShiftedGaussian* ShiftedGaussianValues_;
179 /** Verbosity level */
180 G4int Verbosity_;
181 /** Structure that contains the values for sampling the Watt fission
182 * spectrum
183 */
184 WattSpectrumConstants* WattConstants_;
185
186 // Pointers to external classes
187 /** Pointer to the CLHEP random number generator. */
188 CLHEP::HepRandomEngine* RandomEngine_;
189
190 // Internal variables for use with sampling a Gaussian distribution.
191 /** Declares whether the second paired random number has been already
192 * returned.
193 */
194 G4bool NextGaussianIsStoredInMemory_;
195 /** Contains the first of the two paired random numbers from the
196 * Gaussian distribution sampling.
197 */
198 G4double GaussianOne_;
199 /** Contains the second of the two paired random numbers from the
200 * Gaussian distribution sampling.
201 */
202 G4double GaussianTwo_;
203 /** Defines the tolerance that ShiftParameters() must match. */
204 G4double Tolerance_;
205 // Functions
206 /** Check to see if the user requested parameters have already been
207 * calculated. If they have, it recalls the stored parameters and sets
208 * them as the current values.
209 */
210 G4bool CheckAndSetParameters();
211 /** Evaluates the constants that are required for the Watt fission spectrum
212 * sampling.
213 */
214 void EvaluateWattConstants();
215 /** Samples a Gaussian distribution defined by the internal class variables
216 * NewMean_ and NewStdDev_.
217 */
218 G4double SampleGaussian();
219 /** Sets the mean and standard deviation of the Gaussian distribution
220 * sampled by this class when \p POSITIVE values are requested.
221 * ShiftMean() performs two different operations based on the requested
222 * data type.
223 * - \p INTEGER: Iteratively searches for an adjusted mean that produces
224 * the same result as the mean requested by the implementor. In this
225 * instance the standard deviation is not adjusted.
226 * - \p DOUBLE: Adjusts the standard deviation of the Gaussian distribution
227 * so that the first seven standard deviations occur are all positive.
228 * The chance that a negative value will result using this method is
229 * 2.56E<sup>-12</sup>
230 */
231 void ShiftParameters(G4FFGEnumerations::GaussianReturnType Type);
232
233 // Destructor function(s)
234 public:
235 /** Default deconstructor. */
236 ~G4FPYSamplingOps();
237 };
238
239 #endif /* G4FPYSAMPLINGOPS_HH */
240