| Geant4 Cross Reference |
1 #include "CLHEP/Random/RandGaussZiggurat.h" 1 #include "CLHEP/Random/RandGaussZiggurat.h"
2 #include "CLHEP/Units/PhysicalConstants.h" 2 #include "CLHEP/Units/PhysicalConstants.h"
3 #include <iostream> 3 #include <iostream>
4 #include <cmath> // for std::log() 4 #include <cmath> // for std::log()
5 5
6 namespace CLHEP { 6 namespace CLHEP {
7 7
8 CLHEP_THREAD_LOCAL unsigned long RandGaussZigg 8 CLHEP_THREAD_LOCAL unsigned long RandGaussZiggurat::kn[128], RandGaussZiggurat::ke[256];
9 CLHEP_THREAD_LOCAL float RandGaussZiggurat::wn 9 CLHEP_THREAD_LOCAL float RandGaussZiggurat::wn[128],RandGaussZiggurat::fn[128],RandGaussZiggurat::we[256],RandGaussZiggurat::fe[256];
10 CLHEP_THREAD_LOCAL bool RandGaussZiggurat::zig 10 CLHEP_THREAD_LOCAL bool RandGaussZiggurat::ziggurat_is_init = false;
11 11
12 HepRandomEngine & RandGaussZiggurat::engine() 12 HepRandomEngine & RandGaussZiggurat::engine() {return RandGauss::engine();}
13 13
14 RandGaussZiggurat::~RandGaussZiggurat() { 14 RandGaussZiggurat::~RandGaussZiggurat() {
15 } 15 }
16 16
17 std::string RandGaussZiggurat::name() const 17 std::string RandGaussZiggurat::name() const
18 { 18 {
19 return "RandGaussZiggurat"; 19 return "RandGaussZiggurat";
20 } 20 }
21 21
22 bool RandGaussZiggurat::ziggurat_init() 22 bool RandGaussZiggurat::ziggurat_init()
23 { 23 {
24 const double rzm1 = 2147483648.0, rzm2 = 429 24 const double rzm1 = 2147483648.0, rzm2 = 4294967296.;
25 double dn=3.442619855899,tn=dn,vn=9.91256303 25 double dn=3.442619855899,tn=dn,vn=9.91256303526217e-3, q;
26 double de=7.697117470131487, te=de, ve=3.949 26 double de=7.697117470131487, te=de, ve=3.949659822581572e-3;
27 int i; 27 int i;
28 28
29 /* Set up tables for RNOR */ 29 /* Set up tables for RNOR */
30 q=vn/std::exp(-.5*dn*dn); 30 q=vn/std::exp(-.5*dn*dn);
31 kn[0]=(unsigned long)((dn/q)*rzm1); 31 kn[0]=(unsigned long)((dn/q)*rzm1);
32 kn[1]=0; 32 kn[1]=0;
33 33
34 wn[0]=q/rzm1; 34 wn[0]=q/rzm1;
35 wn[127]=dn/rzm1; 35 wn[127]=dn/rzm1;
36 36
37 fn[0]=1.; 37 fn[0]=1.;
38 fn[127]=std::exp(-.5*dn*dn); 38 fn[127]=std::exp(-.5*dn*dn);
39 39
40 for(i=126;i>=1;i--) { 40 for(i=126;i>=1;i--) {
41 dn=std::sqrt(-2.*std::log(vn/dn+std::exp(- 41 dn=std::sqrt(-2.*std::log(vn/dn+std::exp(-.5*dn*dn)));
42 kn[i+1]=(unsigned long)((dn/tn)*rzm1); 42 kn[i+1]=(unsigned long)((dn/tn)*rzm1);
43 tn=dn; 43 tn=dn;
44 fn[i]=std::exp(-.5*dn*dn); 44 fn[i]=std::exp(-.5*dn*dn);
45 wn[i]=dn/rzm1; 45 wn[i]=dn/rzm1;
46 } 46 }
47 47
48 /* Set up tables for REXP */ 48 /* Set up tables for REXP */
49 q = ve/std::exp(-de); 49 q = ve/std::exp(-de);
50 ke[0]=(unsigned long)((de/q)*rzm2); 50 ke[0]=(unsigned long)((de/q)*rzm2);
51 ke[1]=0; 51 ke[1]=0;
52 52
53 we[0]=q/rzm2; 53 we[0]=q/rzm2;
54 we[255]=de/rzm2; 54 we[255]=de/rzm2;
55 55
56 fe[0]=1.; 56 fe[0]=1.;
57 fe[255]=std::exp(-de); 57 fe[255]=std::exp(-de);
58 58
59 for(i=254;i>=1;i--) { 59 for(i=254;i>=1;i--) {
60 de=-std::log(ve/de+std::exp(-de)); 60 de=-std::log(ve/de+std::exp(-de));
61 ke[i+1]= (unsigned long)((de/te)*rzm2); 61 ke[i+1]= (unsigned long)((de/te)*rzm2);
62 te=de; 62 te=de;
63 fe[i]=std::exp(-de); 63 fe[i]=std::exp(-de);
64 we[i]=de/rzm2; 64 we[i]=de/rzm2;
65 } 65 }
66 ziggurat_is_init=true; 66 ziggurat_is_init=true;
67 67
68 //std::cout<<"Done RandGaussZiggurat::ziggur 68 //std::cout<<"Done RandGaussZiggurat::ziggurat_init()"<<std::endl;
69 69
70 return true; 70 return true;
71 } 71 }
72 72
73 float RandGaussZiggurat::ziggurat_nfix(long hz 73 float RandGaussZiggurat::ziggurat_nfix(long hz,HepRandomEngine* anEngine)
74 { 74 {
75 if(!ziggurat_is_init) ziggurat_init(); 75 if(!ziggurat_is_init) ziggurat_init();
76 const float r = 3.442620f; /* The start 76 const float r = 3.442620f; /* The start of the right tail */
77 float x, y; 77 float x, y;
78 unsigned long iz=hz&127; 78 unsigned long iz=hz&127;
79 for(;;) 79 for(;;)
80 { 80 {
81 x=hz*wn[iz]; /* iz==0, handles the ba 81 x=hz*wn[iz]; /* iz==0, handles the base strip */
82 if(iz==0) { 82 if(iz==0) {
83 do { 83 do {
84 /* change to (1.0 - UNI) as argument t 84 /* change to (1.0 - UNI) as argument to std::log(), because CLHEP generates [0,1),
85 while the original UNI generates (0 85 while the original UNI generates (0,1] */
86 x=-std::log(1.0 - ziggurat_UNI(anEngin 86 x=-std::log(1.0 - ziggurat_UNI(anEngine))*0.2904764; /* .2904764 is 1/r */
87 y=-std::log(1.0 - ziggurat_UNI(anEngin 87 y=-std::log(1.0 - ziggurat_UNI(anEngine));
88 } while(y+y<x*x); 88 } while(y+y<x*x);
89 return (hz>0)? r+x : -r-x; 89 return (hz>0)? r+x : -r-x;
90 } 90 }
91 /* iz>0, handle the wedges of other strips 91 /* iz>0, handle the wedges of other strips */
92 if( fn[iz]+(1.0 - ziggurat_UNI(anEngine))* 92 if( fn[iz]+(1.0 - ziggurat_UNI(anEngine))*(fn[iz-1]-fn[iz]) < std::exp(-.5*x*x) ) return x;
93 93
94 /* initiate, try to exit for(;;) for loop* 94 /* initiate, try to exit for(;;) for loop*/
95 hz=(signed)ziggurat_SHR3(anEngine); 95 hz=(signed)ziggurat_SHR3(anEngine);
96 iz=hz&127; 96 iz=hz&127;
97 if((unsigned long)std::abs(hz)<kn[iz]) ret 97 if((unsigned long)std::abs(hz)<kn[iz]) return (hz*wn[iz]);
98 } 98 }
99 } 99 }
100 100
101 double RandGaussZiggurat::operator()() { 101 double RandGaussZiggurat::operator()() {
102 return ziggurat_RNOR(localEngine.get()) * de 102 return ziggurat_RNOR(localEngine.get()) * defaultStdDev + defaultMean;
103 } 103 }
104 104
105 double RandGaussZiggurat::operator()( double m 105 double RandGaussZiggurat::operator()( double mean, double stdDev ) {
106 return ziggurat_RNOR(localEngine.get()) * st 106 return ziggurat_RNOR(localEngine.get()) * stdDev + mean;
107 } 107 }
108 108
109 void RandGaussZiggurat::shootArray( const int 109 void RandGaussZiggurat::shootArray( const int size, float* vect, float mean, float stdDev )
110 { 110 {
111 for (int i=0; i<size; ++i) { 111 for (int i=0; i<size; ++i) {
112 vect[i] = shoot(mean,stdDev); 112 vect[i] = shoot(mean,stdDev);
113 } 113 }
114 } 114 }
115 115
116 void RandGaussZiggurat::shootArray( const int 116 void RandGaussZiggurat::shootArray( const int size, double* vect, double mean, double stdDev )
117 { 117 {
118 for (int i=0; i<size; ++i) { 118 for (int i=0; i<size; ++i) {
119 vect[i] = shoot(mean,stdDev); 119 vect[i] = shoot(mean,stdDev);
120 } 120 }
121 } 121 }
122 122
123 void RandGaussZiggurat::shootArray( HepRandomE 123 void RandGaussZiggurat::shootArray( HepRandomEngine* anEngine, const int size, float* vect, float mean, float stdDev )
124 { 124 {
125 for (int i=0; i<size; ++i) { 125 for (int i=0; i<size; ++i) {
126 vect[i] = shoot(anEngine,mean,stdDev); 126 vect[i] = shoot(anEngine,mean,stdDev);
127 } 127 }
128 } 128 }
129 129
130 void RandGaussZiggurat::shootArray( HepRandomE 130 void RandGaussZiggurat::shootArray( HepRandomEngine* anEngine, const int size, double* vect, double mean, double stdDev )
131 { 131 {
132 for (int i=0; i<size; ++i) { 132 for (int i=0; i<size; ++i) {
133 vect[i] = shoot(anEngine,mean,stdDev); 133 vect[i] = shoot(anEngine,mean,stdDev);
134 } 134 }
135 } 135 }
136 136
137 void RandGaussZiggurat::fireArray( const int s 137 void RandGaussZiggurat::fireArray( const int size, float* vect)
138 { 138 {
139 for (int i=0; i<size; ++i) { 139 for (int i=0; i<size; ++i) {
140 vect[i] = fire( defaultMean, defaultStdDe 140 vect[i] = fire( defaultMean, defaultStdDev );
141 } 141 }
142 } 142 }
143 143
144 void RandGaussZiggurat::fireArray( const int s 144 void RandGaussZiggurat::fireArray( const int size, double* vect)
145 { 145 {
146 for (int i=0; i<size; ++i) { 146 for (int i=0; i<size; ++i) {
147 vect[i] = fire( defaultMean, defaultStdDe 147 vect[i] = fire( defaultMean, defaultStdDev );
148 } 148 }
149 } 149 }
150 150
151 void RandGaussZiggurat::fireArray( const int s 151 void RandGaussZiggurat::fireArray( const int size, float* vect, float mean, float stdDev )
152 { 152 {
153 for (int i=0; i<size; ++i) { 153 for (int i=0; i<size; ++i) {
154 vect[i] = fire( mean, stdDev ); 154 vect[i] = fire( mean, stdDev );
155 } 155 }
156 } 156 }
157 157
158 void RandGaussZiggurat::fireArray( const int s 158 void RandGaussZiggurat::fireArray( const int size, double* vect, double mean, double stdDev )
159 { 159 {
160 for (int i=0; i<size; ++i) { 160 for (int i=0; i<size; ++i) {
161 vect[i] = fire( mean, stdDev ); 161 vect[i] = fire( mean, stdDev );
162 } 162 }
163 } 163 }
164 164
165 std::ostream & RandGaussZiggurat::put ( std::o 165 std::ostream & RandGaussZiggurat::put ( std::ostream & os ) const {
166 int pr=os.precision(20); 166 int pr=os.precision(20);
167 os << " " << name() << "\n"; 167 os << " " << name() << "\n";
168 RandGauss::put(os); 168 RandGauss::put(os);
169 os.precision(pr); 169 os.precision(pr);
170 return os; 170 return os;
171 } 171 }
172 172
173 std::istream & RandGaussZiggurat::get ( std::i 173 std::istream & RandGaussZiggurat::get ( std::istream & is ) {
174 std::string inName; 174 std::string inName;
175 is >> inName; 175 is >> inName;
176 if (inName != name()) { 176 if (inName != name()) {
177 is.clear(std::ios::badbit | is.rdstate()); 177 is.clear(std::ios::badbit | is.rdstate());
178 std::cerr << "Mismatch when expecting to r 178 std::cerr << "Mismatch when expecting to read state of a "
179 << name() << " distribution\n" 179 << name() << " distribution\n"
180 << "Name found was " << inName 180 << "Name found was " << inName
181 << "\nistream is left in the badbit st 181 << "\nistream is left in the badbit state\n";
182 return is; 182 return is;
183 } 183 }
184 RandGauss::get(is); 184 RandGauss::get(is);
185 return is; 185 return is;
186 } 186 }
187 187
188 } // namespace CLHEP 188 } // namespace CLHEP
189 189