| Geant4 Cross Reference |
1 // 1 //
2 // ******************************************* 2 // ********************************************************************
3 // * License and Disclaimer 3 // * License and Disclaimer *
4 // * 4 // * *
5 // * The Geant4 software is copyright of th 5 // * The Geant4 software is copyright of the Copyright Holders of *
6 // * the Geant4 Collaboration. It is provided 6 // * the Geant4 Collaboration. It is provided under the terms and *
7 // * conditions of the Geant4 Software License 7 // * conditions of the Geant4 Software License, included in the file *
8 // * LICENSE and available at http://cern.ch/ 8 // * LICENSE and available at http://cern.ch/geant4/license . These *
9 // * include a list of copyright holders. 9 // * include a list of copyright holders. *
10 // * 10 // * *
11 // * Neither the authors of this software syst 11 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing fin 12 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warran 13 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assum 14 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file 15 // * use. Please see the license in the file LICENSE and URL above *
16 // * for the full disclaimer and the limitatio 16 // * for the full disclaimer and the limitation of liability. *
17 // * 17 // * *
18 // * This code implementation is the result 18 // * This code implementation is the result of the scientific and *
19 // * technical work of the GEANT4 collaboratio 19 // * technical work of the GEANT4 collaboration. *
20 // * By using, copying, modifying or distri 20 // * By using, copying, modifying or distributing the software (or *
21 // * any work based on the software) you ag 21 // * any work based on the software) you agree to acknowledge its *
22 // * use in resulting scientific publicati 22 // * use in resulting scientific publications, and indicate your *
23 // * acceptance of all terms of the Geant4 Sof 23 // * acceptance of all terms of the Geant4 Software license. *
24 // ******************************************* 24 // ********************************************************************
25 // 25 //
26 // 26 //
27 // 27 //
28 // << 28 //
29 // ------------------------------------------- 29 // ---------------------------------------------------------------------------
30 // GEANT 4 class header file << 30 // GEANT 4 class header file
31 // ------------------------------------------- 31 // ---------------------------------------------------------------------------
32 // Class description: 32 // Class description:
33 // 33 //
34 // Utility functions << 34 // Utility functions
35 35
36 // History: 36 // History:
37 // 37 //
38 // 24.08.17 - E.Tcherniaev, added G4RandomRadi 38 // 24.08.17 - E.Tcherniaev, added G4RandomRadiusInRing, G4RandomPointInEllipse
39 // G4RandomPointOnEll 39 // G4RandomPointOnEllipse, G4RandomPointOnEllipsoid
40 // 07.11.08 - P.Gumplinger, based on implement 40 // 07.11.08 - P.Gumplinger, based on implementation in G4OpBoundaryProcess
41 // 41 //
42 // ------------------------------------------- 42 // ---------------------------------------------------------------------------
43 43
44 #ifndef G4RANDOMTOOLS_HH 44 #ifndef G4RANDOMTOOLS_HH
45 #define G4RANDOMTOOLS_HH 45 #define G4RANDOMTOOLS_HH
46 46
47 #include <CLHEP/Units/PhysicalConstants.h> 47 #include <CLHEP/Units/PhysicalConstants.h>
48 48
49 #include "G4RandomDirection.hh" <<
50 #include "G4ThreeVector.hh" <<
51 #include "G4TwoVector.hh" <<
52 #include "Randomize.hh" <<
53 #include "globals.hh" 49 #include "globals.hh"
>> 50 #include "Randomize.hh"
>> 51 #include "G4TwoVector.hh"
>> 52 #include "G4ThreeVector.hh"
>> 53 #include "G4RandomDirection.hh"
54 54
55 // ------------------------------------------- 55 // ---------------------------------------------------------------------------
56 // Returns a random lambertian unit vector (re 56 // Returns a random lambertian unit vector (rejection sampling)
57 // 57 //
58 inline G4ThreeVector G4LambertianRand(const G4 58 inline G4ThreeVector G4LambertianRand(const G4ThreeVector& normal)
59 { 59 {
60 G4ThreeVector vect; 60 G4ThreeVector vect;
61 G4double ndotv; 61 G4double ndotv;
62 G4int count = 0; << 62 G4int count=0;
63 const G4int max_trials = 1024; 63 const G4int max_trials = 1024;
64 64
65 do 65 do
66 { 66 {
67 ++count; 67 ++count;
68 vect = G4RandomDirection(); << 68 vect = G4RandomDirection();
69 ndotv = normal * vect; 69 ndotv = normal * vect;
70 70
71 if(ndotv < 0.0) << 71 if (ndotv < 0.0)
72 { 72 {
73 vect = -vect; << 73 vect = -vect;
74 ndotv = -ndotv; 74 ndotv = -ndotv;
75 } 75 }
76 76
77 } while(!(G4UniformRand() < ndotv) && (count << 77 } while (!(G4UniformRand() < ndotv) && (count < max_trials));
78 78
79 return vect; 79 return vect;
80 } 80 }
81 81
82 // ------------------------------------------- 82 // ---------------------------------------------------------------------------
83 // Chooses a random vector within a plane give 83 // Chooses a random vector within a plane given by the unit normal
84 // 84 //
85 inline G4ThreeVector G4PlaneVectorRand(const G 85 inline G4ThreeVector G4PlaneVectorRand(const G4ThreeVector& normal)
86 { 86 {
87 G4ThreeVector vec1 = normal.orthogonal(); 87 G4ThreeVector vec1 = normal.orthogonal();
88 G4ThreeVector vec2 = vec1.cross(normal); 88 G4ThreeVector vec2 = vec1.cross(normal);
89 89
90 G4double phi = CLHEP::twopi * G4UniformRa << 90 G4double phi = CLHEP::twopi*G4UniformRand();
91 G4double cosphi = std::cos(phi); 91 G4double cosphi = std::cos(phi);
92 G4double sinphi = std::sin(phi); 92 G4double sinphi = std::sin(phi);
93 93
94 return cosphi * vec1 + sinphi * vec2; 94 return cosphi * vec1 + sinphi * vec2;
95 } 95 }
96 96
97 // ------------------------------------------- 97 // ---------------------------------------------------------------------------
98 // Returns a random radius in annular ring 98 // Returns a random radius in annular ring
99 // 99 //
100 inline G4double G4RandomRadiusInRing(G4double 100 inline G4double G4RandomRadiusInRing(G4double rmin, G4double rmax)
101 { 101 {
102 if(rmin == rmax) << 102 if (rmin == rmax)
103 { 103 {
104 return rmin; 104 return rmin;
105 } 105 }
106 G4double k = G4UniformRand(); 106 G4double k = G4UniformRand();
107 return (rmin <= 0) ? rmax * std::sqrt(k) << 107 return (rmin <= 0) ? rmax*std::sqrt(k)
108 : std::sqrt(k * rmax * rm << 108 : std::sqrt(k*rmax*rmax + (1.-k)*rmin*rmin);
109 } 109 }
110 110
111 // ------------------------------------------- 111 // ---------------------------------------------------------------------------
112 // Returns a random point in ellipse (x/a)^2 + 112 // Returns a random point in ellipse (x/a)^2 + (y/b)^2 = 1
113 // (rejection sampling) 113 // (rejection sampling)
114 // 114 //
115 inline G4TwoVector G4RandomPointInEllipse(G4do 115 inline G4TwoVector G4RandomPointInEllipse(G4double a, G4double b)
116 { 116 {
117 G4double aa = (a * a == 0) ? 0 : 1 / (a * a) << 117 G4double aa = (a*a == 0) ? 0 : 1/(a*a);
118 G4double bb = (b * b == 0) ? 0 : 1 / (b * b) << 118 G4double bb = (b*b == 0) ? 0 : 1/(b*b);
119 for(G4int i = 0; i < 1000; ++i) << 119 for (G4int i=0; i<1000; ++i)
120 { 120 {
121 G4double x = a * (2 * G4UniformRand() - 1) << 121 G4double x = a*(2*G4UniformRand() - 1);
122 G4double y = b * (2 * G4UniformRand() - 1) << 122 G4double y = b*(2*G4UniformRand() - 1);
123 if(x * x * aa + y * y * bb <= 1) << 123 if (x*x*aa + y*y*bb <= 1) return G4TwoVector(x,y);
124 return G4TwoVector(x, y); <<
125 } 124 }
126 return G4TwoVector(0, 0); << 125 return G4TwoVector(0,0);
127 } 126 }
128 127
129 // ------------------------------------------- 128 // ---------------------------------------------------------------------------
130 // Returns a random point on ellipse (x/a)^2 + 129 // Returns a random point on ellipse (x/a)^2 + (y/b)^2 = 1
131 // (rejection sampling) 130 // (rejection sampling)
132 // 131 //
133 inline G4TwoVector G4RandomPointOnEllipse(G4do 132 inline G4TwoVector G4RandomPointOnEllipse(G4double a, G4double b)
134 { 133 {
135 G4double A = std::abs(a); << 134 G4double A = std::abs(a);
136 G4double B = std::abs(b); << 135 G4double B = std::abs(b);
137 G4double mu_max = std::max(A, B); << 136 G4double mu_max = std::max(A,B);
138 137
139 G4double x, y; << 138 G4double x,y;
140 for(G4int i = 0; i < 1000; ++i) << 139 for (G4int i=0; i<1000; ++i)
141 { 140 {
142 G4double phi = CLHEP::twopi * G4UniformRan << 141 G4double phi = CLHEP::twopi*G4UniformRand();
143 x = std::cos(phi); << 142 x = std::cos(phi);
144 y = std::sin(phi); << 143 y = std::sin(phi);
145 G4double mu = std::sqrt((B * x) * (B * x) << 144 G4double mu = std::sqrt((B*x)*(B*x) + (A*y)*(A*y));
146 if(mu_max * G4UniformRand() <= mu) << 145 if (mu_max*G4UniformRand() <= mu) break;
147 break; <<
148 } 146 }
149 return G4TwoVector(A * x, B * y); << 147 return G4TwoVector(A*x,B*y);
150 } 148 }
151 149
152 // ------------------------------------------- 150 // ---------------------------------------------------------------------------
153 // Returns a random point on ellipsoid (x/a)^2 151 // Returns a random point on ellipsoid (x/a)^2 + (y/b)^2 + (z/c)^2 = 1
154 // (rejection sampling) 152 // (rejection sampling)
155 // 153 //
156 inline G4ThreeVector G4RandomPointOnEllipsoid( << 154 inline
157 << 155 G4ThreeVector G4RandomPointOnEllipsoid(G4double a, G4double b, G4double c)
158 { 156 {
159 G4double A = std::abs(a); << 157 G4double A = std::abs(a);
160 G4double B = std::abs(b); << 158 G4double B = std::abs(b);
161 G4double C = std::abs(c); << 159 G4double C = std::abs(c);
162 G4double mu_max = std::max(std::max(A * B, A << 160 G4double mu_max = std::max(std::max(A*B,A*C),B*C);
163 161
164 G4ThreeVector p; 162 G4ThreeVector p;
165 for(G4int i = 0; i < 1000; ++i) << 163 for (G4int i=0; i<1000; ++i)
166 { 164 {
167 p = G4RandomDirection(); << 165 p = G4RandomDirection();
168 G4double xbc = p.x() * B * C; << 166 G4double xbc = p.x()*B*C;
169 G4double yac = p.y() * A * C; << 167 G4double yac = p.y()*A*C;
170 G4double zab = p.z() * A * B; << 168 G4double zab = p.z()*A*B;
171 G4double mu = std::sqrt(xbc * xbc + yac * << 169 G4double mu = std::sqrt(xbc*xbc + yac*yac + zab*zab);
172 if(mu_max * G4UniformRand() <= mu) << 170 if (mu_max*G4UniformRand() <= mu) break;
173 break; <<
174 } 171 }
175 return G4ThreeVector(A * p.x(), B * p.y(), C << 172 return G4ThreeVector(A*p.x(),B*p.y(),C*p.z());
176 } 173 }
177 174
178 #endif /* G4RANDOMTOOLS_HH */ << 175 #endif /* G4RANDOMTOOLS_HH */
179 176