| Geant4 Cross Reference |
>> 1 // $Id:$
1 // -*- C++ -*- 2 // -*- C++ -*-
2 // 3 //
3 // ------------------------------------------- 4 // -----------------------------------------------------------------------
4 // Hep Random 5 // Hep Random
5 // --- DualRand --- 6 // --- DualRand ---
6 // class implementation file 7 // class implementation file
7 // ------------------------------------------- 8 // -----------------------------------------------------------------------
8 // Exclusive or of a feedback shift register 9 // Exclusive or of a feedback shift register and integer congruence
9 // random number generator. The feedback shi 10 // random number generator. The feedback shift register uses offsets
10 // 127 and 97. The integer congruence genera 11 // 127 and 97. The integer congruence generator uses a different
11 // multiplier for each stream. The multiplie 12 // multiplier for each stream. The multipliers are chosen to give
12 // full period and maximum "potency" for modu 13 // full period and maximum "potency" for modulo 2^32. The period of
13 // the combined random number generator is 2^ 14 // the combined random number generator is 2^159 - 2^32, and the
14 // sequences are different for each stream (n 15 // sequences are different for each stream (not just started in a
15 // different place). 16 // different place).
16 // 17 //
17 // In the original generator used on ACPMAPS: 18 // In the original generator used on ACPMAPS:
18 // The feedback shift register generates 24 b 19 // The feedback shift register generates 24 bits at a time, and
19 // the high order 24 bits of the integer cong 20 // the high order 24 bits of the integer congruence generator are
20 // used. 21 // used.
21 // 22 //
22 // Instead, to conform with more modern engin 23 // Instead, to conform with more modern engine concepts, we generate
23 // 32 bits at a time and use the full 32 bits 24 // 32 bits at a time and use the full 32 bits of the congruence
24 // generator. 25 // generator.
25 // 26 //
26 // References: 27 // References:
27 // Knuth 28 // Knuth
28 // Tausworthe 29 // Tausworthe
29 // Golomb 30 // Golomb
30 //============================================ 31 //=========================================================================
31 // Ken Smith - Removed pow() from flat() 32 // Ken Smith - Removed pow() from flat() method: 21 Jul 1998
32 // - Added conversion operators 33 // - Added conversion operators: 6 Aug 1998
33 // J. Marraffino - Added some explicit casts 34 // J. Marraffino - Added some explicit casts to deal with
34 // machines where sizeof(int) 35 // machines where sizeof(int) != sizeof(long) 22 Aug 1998
35 // M. Fischler - Modified constructors taki 36 // M. Fischler - Modified constructors taking seeds to not
36 // depend on numEngines (same seeds sho 37 // depend on numEngines (same seeds should
37 // produce same sequences). Default st 38 // produce same sequences). Default still
38 // depends on numEngines. 14 Sep 1 39 // depends on numEngines. 14 Sep 1998
39 // - Modified use of the variou 40 // - Modified use of the various exponents of 2
40 // to avoid per-instance spac 41 // to avoid per-instance space overhead and
41 // correct the rounding proce 42 // correct the rounding procedure 15 Sep 1998
42 // J. Marraffino - Remove dependence on hepSt 43 // J. Marraffino - Remove dependence on hepString class 13 May 1999
43 // M. Fischler - Put endl at end of a save 44 // M. Fischler - Put endl at end of a save 10 Apr 2001
44 // M. Fischler - In restore, checkFile for 45 // M. Fischler - In restore, checkFile for file not found 03 Dec 2004
45 // M. Fischler - methods for distrib. insta 46 // M. Fischler - methods for distrib. instacne save/restore 12/8/04
46 // M. Fischler - split get() into tag valid 47 // M. Fischler - split get() into tag validation and
47 // getState() for anonymous r 48 // getState() for anonymous restores 12/27/04
48 // Mark Fischler - methods for vector save/re 49 // Mark Fischler - methods for vector save/restore 3/7/05
49 // M. Fischler - State-saving using only in 50 // M. Fischler - State-saving using only ints, for portability 4/12/05
50 // 51 //
51 //============================================ 52 //=========================================================================
52 53
53 #include "CLHEP/Random/DualRand.h" 54 #include "CLHEP/Random/DualRand.h"
54 #include "CLHEP/Random/engineIDulong.h" 55 #include "CLHEP/Random/engineIDulong.h"
55 #include "CLHEP/Utility/atomic_int.h" <<
56 <<
57 #include <atomic> <<
58 #include <ostream> <<
59 #include <string.h> // for strcmp 56 #include <string.h> // for strcmp
60 #include <vector> <<
61 #include <iostream> <<
62 57
63 namespace CLHEP { << 58 using namespace std;
64 59
65 namespace { << 60 namespace CLHEP {
66 // Number of instances with automatic seed s <<
67 CLHEP_ATOMIC_INT_TYPE numberOfEngines(0); <<
68 } <<
69 61
70 static const int MarkerLen = 64; // Enough roo 62 static const int MarkerLen = 64; // Enough room to hold a begin or end marker.
71 63
72 std::string DualRand::name() const {return "Du 64 std::string DualRand::name() const {return "DualRand";}
73 65
>> 66 // Number of instances with automatic seed selection
>> 67 int DualRand::numEngines = 0;
>> 68
74 // The following constructors (excluding the i 69 // The following constructors (excluding the istream constructor) fill
75 // the bits of the tausworthe and the starting 70 // the bits of the tausworthe and the starting state of the integer
76 // congruence based on the seed. In addition, 71 // congruence based on the seed. In addition, it sets up the multiplier
77 // for the integer congruence based on the str 72 // for the integer congruence based on the stream number, so you have
78 // absolutely independent streams. 73 // absolutely independent streams.
79 74
80 DualRand::DualRand() 75 DualRand::DualRand()
81 : HepRandomEngine(), 76 : HepRandomEngine(),
82 numEngines(numberOfEngines++), <<
83 tausworthe (1234567 + numEngines + 175321), 77 tausworthe (1234567 + numEngines + 175321),
84 integerCong(69607 * tausworthe + 54329, numE 78 integerCong(69607 * tausworthe + 54329, numEngines)
85 { 79 {
86 theSeed = 1234567; 80 theSeed = 1234567;
>> 81 ++numEngines;
87 } 82 }
88 83
89 DualRand::DualRand(long seed) 84 DualRand::DualRand(long seed)
90 : HepRandomEngine(), 85 : HepRandomEngine(),
91 numEngines(0), <<
92 tausworthe ((unsigned int)seed + 175321), 86 tausworthe ((unsigned int)seed + 175321),
93 integerCong(69607 * tausworthe + 54329, 8043 87 integerCong(69607 * tausworthe + 54329, 8043) // MF - not numEngines
94 { 88 {
95 theSeed = seed; 89 theSeed = seed;
96 } 90 }
97 91
98 DualRand::DualRand(std::istream & is) 92 DualRand::DualRand(std::istream & is)
99 : HepRandomEngine(), << 93 : HepRandomEngine()
100 numEngines(0) <<
101 { 94 {
102 is >> *this; 95 is >> *this;
103 } 96 }
104 97
105 DualRand::DualRand(int rowIndex, int colIndex) 98 DualRand::DualRand(int rowIndex, int colIndex)
106 : HepRandomEngine(), 99 : HepRandomEngine(),
107 numEngines(0), <<
108 tausworthe (rowIndex + 1000 * colIndex + 853 100 tausworthe (rowIndex + 1000 * colIndex + 85329),
109 integerCong(69607 * tausworthe + 54329, 1123 101 integerCong(69607 * tausworthe + 54329, 1123) // MF - not numengines
110 { 102 {
111 theSeed = rowIndex; 103 theSeed = rowIndex;
112 } 104 }
113 105
114 DualRand::~DualRand() { } 106 DualRand::~DualRand() { }
115 107
116 double DualRand::flat() { 108 double DualRand::flat() {
117 unsigned int ic ( integerCong ); 109 unsigned int ic ( integerCong );
118 unsigned int t ( tausworthe ); 110 unsigned int t ( tausworthe );
119 return ( (t ^ ic) * twoToMinus_32() + 111 return ( (t ^ ic) * twoToMinus_32() + // most significant part
120 (t >> 11) * twoToMinus_53() + 112 (t >> 11) * twoToMinus_53() + // fill in remaining bits
121 nearlyTwoToMinus_54() // m 113 nearlyTwoToMinus_54() // make sure non-zero
122 ); 114 );
123 } 115 }
124 116
125 void DualRand::flatArray(const int size, doubl 117 void DualRand::flatArray(const int size, double* vect) {
126 for (int i = 0; i < size; ++i) { 118 for (int i = 0; i < size; ++i) {
127 vect[i] = flat(); 119 vect[i] = flat();
128 } 120 }
129 } 121 }
130 122
131 void DualRand::setSeed(long seed, int) { 123 void DualRand::setSeed(long seed, int) {
132 theSeed = seed; 124 theSeed = seed;
133 tausworthe = Tausworthe((unsigned int)seed << 125 tausworthe = Tausworthe((unsigned int)seed + numEngines + 175321);
134 integerCong = IntegerCong(69607 * tausworthe << 126 integerCong = IntegerCong(69607 * tausworthe + 54329, numEngines);
135 } 127 }
136 128
137 void DualRand::setSeeds(const long * seeds, in 129 void DualRand::setSeeds(const long * seeds, int) {
138 setSeed(seeds ? *seeds : 1234567, 0); 130 setSeed(seeds ? *seeds : 1234567, 0);
139 theSeeds = seeds; 131 theSeeds = seeds;
140 } 132 }
141 133
142 void DualRand::saveStatus(const char filename[ 134 void DualRand::saveStatus(const char filename[]) const {
143 std::ofstream outFile(filename, std::ios::ou 135 std::ofstream outFile(filename, std::ios::out);
144 if (!outFile.bad()) { 136 if (!outFile.bad()) {
145 outFile << "Uvec\n"; 137 outFile << "Uvec\n";
146 std::vector<unsigned long> v = put(); 138 std::vector<unsigned long> v = put();
147 for (unsigned int i=0; i<v.size(); ++i) { 139 for (unsigned int i=0; i<v.size(); ++i) {
148 outFile << v[i] << "\n"; 140 outFile << v[i] << "\n";
149 } 141 }
150 } 142 }
151 } 143 }
152 144
153 void DualRand::restoreStatus(const char filena 145 void DualRand::restoreStatus(const char filename[]) {
154 std::ifstream inFile(filename, std::ios::in) 146 std::ifstream inFile(filename, std::ios::in);
155 if (!checkFile ( inFile, filename, engineNam 147 if (!checkFile ( inFile, filename, engineName(), "restoreStatus" )) {
156 std::cerr << " -- Engine state remains un 148 std::cerr << " -- Engine state remains unchanged\n";
157 return; 149 return;
158 } 150 }
159 if ( possibleKeywordInput ( inFile, "Uvec", 151 if ( possibleKeywordInput ( inFile, "Uvec", theSeed ) ) {
160 std::vector<unsigned long> v; 152 std::vector<unsigned long> v;
161 unsigned long xin; 153 unsigned long xin;
162 for (unsigned int ivec=0; ivec < VECTOR_ST 154 for (unsigned int ivec=0; ivec < VECTOR_STATE_SIZE; ++ivec) {
163 inFile >> xin; 155 inFile >> xin;
164 if (!inFile) { 156 if (!inFile) {
165 inFile.clear(std::ios::badbit | inFile 157 inFile.clear(std::ios::badbit | inFile.rdstate());
166 std::cerr << "\nDualRand state (vector 158 std::cerr << "\nDualRand state (vector) description improper."
167 << "\nrestoreStatus has failed." 159 << "\nrestoreStatus has failed."
168 << "\nInput stream is probably mispos 160 << "\nInput stream is probably mispositioned now." << std::endl;
169 return; 161 return;
170 } 162 }
171 v.push_back(xin); 163 v.push_back(xin);
172 } 164 }
173 getState(v); 165 getState(v);
174 return; 166 return;
175 } 167 }
176 168
177 if (!inFile.bad()) { 169 if (!inFile.bad()) {
178 // inFile >> theSeed; removed -- encompas 170 // inFile >> theSeed; removed -- encompased by possibleKeywordInput
179 tausworthe.get(inFile); 171 tausworthe.get(inFile);
180 integerCong.get(inFile); 172 integerCong.get(inFile);
181 } 173 }
182 } 174 }
183 175
184 void DualRand::showStatus() const { 176 void DualRand::showStatus() const {
185 long pr=std::cout.precision(20); << 177 int pr=std::cout.precision(20);
186 std::cout << std::endl; 178 std::cout << std::endl;
187 std::cout << "-------- DualRand engi 179 std::cout << "-------- DualRand engine status ---------"
188 << std::endl; 180 << std::endl;
189 std::cout << "Initial seed = " << t 181 std::cout << "Initial seed = " << theSeed << std::endl;
190 std::cout << "Tausworthe generator = " << s 182 std::cout << "Tausworthe generator = " << std::endl;
191 tausworthe.put(std::cout); 183 tausworthe.put(std::cout);
192 std::cout << "\nIntegerCong generator = " << 184 std::cout << "\nIntegerCong generator = " << std::endl;
193 integerCong.put(std::cout); 185 integerCong.put(std::cout);
194 std::cout << std::endl << "----------------- 186 std::cout << std::endl << "-----------------------------------------"
195 << std::endl; 187 << std::endl;
196 std::cout.precision(pr); 188 std::cout.precision(pr);
197 } 189 }
198 190
199 DualRand::operator double() { <<
200 return flat(); <<
201 } <<
202 <<
203 DualRand::operator float() { 191 DualRand::operator float() {
204 return (float) ( (integerCong ^ tausworthe) 192 return (float) ( (integerCong ^ tausworthe) * twoToMinus_32()
205 + nearlyTwoToMinus_54() ); 193 + nearlyTwoToMinus_54() );
206 // add this so that zero never happe 194 // add this so that zero never happens
207 } 195 }
208 196
209 DualRand::operator unsigned int() { 197 DualRand::operator unsigned int() {
210 return (integerCong ^ tausworthe) & 0xffffff 198 return (integerCong ^ tausworthe) & 0xffffffff;
211 } 199 }
212 200
213 std::ostream & DualRand::put(std::ostream & os 201 std::ostream & DualRand::put(std::ostream & os) const {
214 char beginMarker[] = "DualRand-begin"; 202 char beginMarker[] = "DualRand-begin";
215 os << beginMarker << "\nUvec\n"; 203 os << beginMarker << "\nUvec\n";
216 std::vector<unsigned long> v = put(); 204 std::vector<unsigned long> v = put();
217 for (unsigned int i=0; i<v.size(); ++i) { 205 for (unsigned int i=0; i<v.size(); ++i) {
218 os << v[i] << "\n"; 206 os << v[i] << "\n";
219 } 207 }
220 return os; 208 return os;
221 } 209 }
222 210
223 std::vector<unsigned long> DualRand::put () co 211 std::vector<unsigned long> DualRand::put () const {
224 std::vector<unsigned long> v; 212 std::vector<unsigned long> v;
225 v.push_back (engineIDulong<DualRand>()); 213 v.push_back (engineIDulong<DualRand>());
226 tausworthe.put(v); 214 tausworthe.put(v);
227 integerCong.put(v); 215 integerCong.put(v);
228 return v; 216 return v;
229 } 217 }
230 218
231 std::istream & DualRand::get(std::istream & is 219 std::istream & DualRand::get(std::istream & is) {
232 char beginMarker [MarkerLen]; 220 char beginMarker [MarkerLen];
233 is >> std::ws; 221 is >> std::ws;
234 is.width(MarkerLen); // causes the next rea 222 is.width(MarkerLen); // causes the next read to the char* to be <=
235 // that many bytes, INCLUDING A TERMINAT 223 // that many bytes, INCLUDING A TERMINATION \0
236 // (Stroustrup, section 21.3.2) 224 // (Stroustrup, section 21.3.2)
237 is >> beginMarker; 225 is >> beginMarker;
238 if (strcmp(beginMarker,"DualRand-begin")) { 226 if (strcmp(beginMarker,"DualRand-begin")) {
239 is.clear(std::ios::badbit | is.rdstate()); 227 is.clear(std::ios::badbit | is.rdstate());
240 std::cerr << "\nInput mispositioned or" 228 std::cerr << "\nInput mispositioned or"
241 << "\nDualRand state description missi 229 << "\nDualRand state description missing or"
242 << "\nwrong engine type found." << std 230 << "\nwrong engine type found." << std::endl;
243 return is; 231 return is;
244 } 232 }
245 return getState(is); 233 return getState(is);
246 } 234 }
247 235
248 std::string DualRand::beginTag ( ) { 236 std::string DualRand::beginTag ( ) {
249 return "DualRand-begin"; 237 return "DualRand-begin";
250 } 238 }
251 239
252 std::istream & DualRand::getState ( std::istre 240 std::istream & DualRand::getState ( std::istream & is ) {
253 if ( possibleKeywordInput ( is, "Uvec", theS 241 if ( possibleKeywordInput ( is, "Uvec", theSeed ) ) {
254 std::vector<unsigned long> v; 242 std::vector<unsigned long> v;
255 unsigned long uu; 243 unsigned long uu;
256 for (unsigned int ivec=0; ivec < VECTOR_ST 244 for (unsigned int ivec=0; ivec < VECTOR_STATE_SIZE; ++ivec) {
257 is >> uu; 245 is >> uu;
258 if (!is) { 246 if (!is) {
259 is.clear(std::ios::badbit | is.rdstate 247 is.clear(std::ios::badbit | is.rdstate());
260 std::cerr << "\nDualRand state (vector 248 std::cerr << "\nDualRand state (vector) description improper."
261 << "\ngetState() has failed." 249 << "\ngetState() has failed."
262 << "\nInput stream is probably mispos 250 << "\nInput stream is probably mispositioned now." << std::endl;
263 return is; 251 return is;
264 } 252 }
265 v.push_back(uu); 253 v.push_back(uu);
266 } 254 }
267 getState(v); 255 getState(v);
268 return (is); 256 return (is);
269 } 257 }
270 258
271 // is >> theSeed; Removed, encompassed by po 259 // is >> theSeed; Removed, encompassed by possibleKeywordInput()
272 260
273 char endMarker [MarkerLen]; 261 char endMarker [MarkerLen];
274 tausworthe.get(is); 262 tausworthe.get(is);
275 integerCong.get(is); 263 integerCong.get(is);
276 is >> std::ws; 264 is >> std::ws;
277 is.width(MarkerLen); 265 is.width(MarkerLen);
278 is >> endMarker; 266 is >> endMarker;
279 if (strcmp(endMarker,"DualRand-end")) { 267 if (strcmp(endMarker,"DualRand-end")) {
280 is.clear(std::ios::badbit | is.rdstate()); 268 is.clear(std::ios::badbit | is.rdstate());
281 std::cerr << "DualRand state description i 269 std::cerr << "DualRand state description incomplete."
282 << "\nInput stream is probably misposi 270 << "\nInput stream is probably mispositioned now." << std::endl;
283 return is; 271 return is;
284 } 272 }
285 return is; 273 return is;
286 } 274 }
287 275
288 bool DualRand::get(const std::vector<unsigned 276 bool DualRand::get(const std::vector<unsigned long> & v) {
289 if ((v[0] & 0xffffffffUL) != engineIDulong<D 277 if ((v[0] & 0xffffffffUL) != engineIDulong<DualRand>()) {
290 std::cerr << 278 std::cerr <<
291 "\nDualRand get:state vector has wrong I 279 "\nDualRand get:state vector has wrong ID word - state unchanged\n";
292 return false; 280 return false;
293 } 281 }
294 if (v.size() != VECTOR_STATE_SIZE) { 282 if (v.size() != VECTOR_STATE_SIZE) {
295 std::cerr << "\nDualRand get:state vector 283 std::cerr << "\nDualRand get:state vector has wrong size: "
296 << v.size() << " - state unchanged\n"; 284 << v.size() << " - state unchanged\n";
297 return false; 285 return false;
298 } 286 }
299 return getState(v); 287 return getState(v);
300 } 288 }
301 289
302 bool DualRand::getState (const std::vector<uns 290 bool DualRand::getState (const std::vector<unsigned long> & v) {
303 std::vector<unsigned long>::const_iterator i 291 std::vector<unsigned long>::const_iterator iv = v.begin()+1;
304 if (!tausworthe.get(iv)) return false; 292 if (!tausworthe.get(iv)) return false;
305 if (!integerCong.get(iv)) return false; 293 if (!integerCong.get(iv)) return false;
306 if (iv != v.end()) { 294 if (iv != v.end()) {
307 std::cerr << 295 std::cerr <<
308 "\nDualRand get:state vector has wrong s 296 "\nDualRand get:state vector has wrong size: " << v.size()
309 << "\n Apparently " << iv-v.begin() 297 << "\n Apparently " << iv-v.begin() << " words were consumed\n";
310 return false; 298 return false;
311 } 299 }
312 return true; 300 return true;
313 } 301 }
314 302
315 DualRand::Tausworthe::Tausworthe() { 303 DualRand::Tausworthe::Tausworthe() {
316 words[0] = 1234567; 304 words[0] = 1234567;
317 for (wordIndex = 1; wordIndex < 4; ++wordInd 305 for (wordIndex = 1; wordIndex < 4; ++wordIndex) {
318 words[wordIndex] = 69607 * words[wordIndex 306 words[wordIndex] = 69607 * words[wordIndex-1] + 54329;
319 } 307 }
320 } 308 }
321 309
322 DualRand::Tausworthe::Tausworthe(unsigned int 310 DualRand::Tausworthe::Tausworthe(unsigned int seed) {
323 words[0] = seed; 311 words[0] = seed;
324 for (wordIndex = 1; wordIndex < 4; ++wordInd 312 for (wordIndex = 1; wordIndex < 4; ++wordIndex) {
325 words[wordIndex] = 69607 * words[wordIndex 313 words[wordIndex] = 69607 * words[wordIndex-1] + 54329;
326 } 314 }
327 } 315 }
328 316
329 DualRand::Tausworthe::operator unsigned int() 317 DualRand::Tausworthe::operator unsigned int() {
330 318
331 // Mathematically: Consider a sequence of bit 319 // Mathematically: Consider a sequence of bits b[n]. Repeatedly form
332 // b[0]' = b[127] ^ b[97]; b[n]' = b[n-1]. Th 320 // b[0]' = b[127] ^ b[97]; b[n]' = b[n-1]. This sequence will have a very
333 // long period (2**127-1 according to Tauswort 321 // long period (2**127-1 according to Tausworthe's work).
334 322
335 // The actual method used relies on the fact t 323 // The actual method used relies on the fact that the operations needed to
336 // form bit 0 for up to 96 iterations never de 324 // form bit 0 for up to 96 iterations never depend on the results of the
337 // previous ones. So you can actually compute 325 // previous ones. So you can actually compute many bits at once. In fact
338 // you can compute 32 at once -- despite 127 - 326 // you can compute 32 at once -- despite 127 - 97 < 32 -- but 24 was used in
339 // the method used in Canopy, where they wante 327 // the method used in Canopy, where they wanted only single-precision float
340 // randoms. I will do 32 here. 328 // randoms. I will do 32 here.
341 329
342 // When you do it this way, this looks disturb 330 // When you do it this way, this looks disturbingly like the dread lagged XOR
343 // Fibonacci. And indeed, it is a lagged Fibo 331 // Fibonacci. And indeed, it is a lagged Fibonacii, F(4,3, op) with the op
344 // being the XOR of a combination of shifts of 332 // being the XOR of a combination of shifts of the two numbers. Although
345 // Tausworthe asserted excellent properties, I 333 // Tausworthe asserted excellent properties, I would be scared to death.
346 // However, the shifting and bit swapping real 334 // However, the shifting and bit swapping really does randomize this in a
347 // serious way. 335 // serious way.
348 336
349 // Statements have been made to the effect tha 337 // Statements have been made to the effect that shift register sequences fail
350 // the parking lot test because they achieve r 338 // the parking lot test because they achieve randomness by multiple foldings,
351 // and this produces a characteristic pattern. 339 // and this produces a characteristic pattern. We observe that in this
352 // specific algorithm, which has a fairly long 340 // specific algorithm, which has a fairly long lever arm, the foldings become
353 // effectively random. This is evidenced by t 341 // effectively random. This is evidenced by the fact that the generator
354 // does pass the Diehard tests, including the 342 // does pass the Diehard tests, including the parking lot test.
355 343
356 // To avoid shuffling of variables in memory, 344 // To avoid shuffling of variables in memory, you either have to use circular
357 // pointers (and those give you ifs, which are 345 // pointers (and those give you ifs, which are also costly) or compute at least
358 // a few iterations at once. We do the latter 346 // a few iterations at once. We do the latter. Although there is a possible
359 // trade of room for more speed, by computing 347 // trade of room for more speed, by computing and saving 256 instead of 128
360 // bits at once, I will stop at this level of 348 // bits at once, I will stop at this level of optimization.
361 349
362 // To remind: Each (32-bit) step takes the XO 350 // To remind: Each (32-bit) step takes the XOR of bits [127-96] with bits
363 // [95-64] and places it in bits [0-31]. But 351 // [95-64] and places it in bits [0-31]. But in the first step, we designate
364 // word0 as bits [0-31], in the second step, w 352 // word0 as bits [0-31], in the second step, word 1 (since the bits it holds
365 // will no longer be needed), then word 2, the 353 // will no longer be needed), then word 2, then word 3. After this, the
366 // stream contains 128 random bits which we wi 354 // stream contains 128 random bits which we will use as 4 valid 32-bit
367 // random numbers. 355 // random numbers.
368 356
369 // Thus at the start of the first step, word[0 357 // Thus at the start of the first step, word[0] contains the newest (used)
370 // 32-bit random, and word[3] the oldest. Af 358 // 32-bit random, and word[3] the oldest. After four steps, word[0] again
371 // contains the newest (now unused) random, an 359 // contains the newest (now unused) random, and word[3] the oldest.
372 // Bit 0 of word[0] is logically the newest bi 360 // Bit 0 of word[0] is logically the newest bit, and bit 31 of word[3]
373 // the oldest. 361 // the oldest.
374 362
375 if (wordIndex <= 0) { 363 if (wordIndex <= 0) {
376 for (wordIndex = 0; wordIndex < 4; ++wordI 364 for (wordIndex = 0; wordIndex < 4; ++wordIndex) {
377 words[wordIndex] = ( (words[(wordIndex+1 365 words[wordIndex] = ( (words[(wordIndex+1) & 3] << 1 ) |
378 (words[word 366 (words[wordIndex] >> 31) )
379 ^ ( (words[(wordIndex+1 367 ^ ( (words[(wordIndex+1) & 3] << 31) |
380 (words[word 368 (words[wordIndex] >> 1) );
381 } 369 }
382 } 370 }
383 return words[--wordIndex] & 0xffffffff; 371 return words[--wordIndex] & 0xffffffff;
384 } 372 }
385 373
386 void DualRand::Tausworthe::put(std::ostream & 374 void DualRand::Tausworthe::put(std::ostream & os) const {
387 char beginMarker[] = "Tausworthe-begin"; 375 char beginMarker[] = "Tausworthe-begin";
388 char endMarker[] = "Tausworthe-end"; 376 char endMarker[] = "Tausworthe-end";
389 377
390 long pr=os.precision(20); << 378 int pr=os.precision(20);
391 os << " " << beginMarker << " "; 379 os << " " << beginMarker << " ";
392 for (int i = 0; i < 4; ++i) { 380 for (int i = 0; i < 4; ++i) {
393 os << words[i] << " "; 381 os << words[i] << " ";
394 } 382 }
395 os << wordIndex; 383 os << wordIndex;
396 os << " " << endMarker << " "; 384 os << " " << endMarker << " ";
397 os << std::endl; 385 os << std::endl;
398 os.precision(pr); 386 os.precision(pr);
399 } 387 }
400 388
401 void DualRand::Tausworthe::put(std::vector<uns 389 void DualRand::Tausworthe::put(std::vector<unsigned long> & v) const {
402 for (int i = 0; i < 4; ++i) { 390 for (int i = 0; i < 4; ++i) {
403 v.push_back(static_cast<unsigned long>(wor 391 v.push_back(static_cast<unsigned long>(words[i]));
404 } 392 }
405 v.push_back(static_cast<unsigned long>(wordI 393 v.push_back(static_cast<unsigned long>(wordIndex));
406 } 394 }
407 395
408 void DualRand::Tausworthe::get(std::istream & 396 void DualRand::Tausworthe::get(std::istream & is) {
409 char beginMarker [MarkerLen]; 397 char beginMarker [MarkerLen];
410 char endMarker [MarkerLen]; 398 char endMarker [MarkerLen];
411 399
412 is >> std::ws; 400 is >> std::ws;
413 is.width(MarkerLen); // causes the next rea 401 is.width(MarkerLen); // causes the next read to the char* to be <=
414 // that many bytes, INCLUDING A TERMINAT 402 // that many bytes, INCLUDING A TERMINATION \0
415 // (Stroustrup, section 21.3.2) 403 // (Stroustrup, section 21.3.2)
416 is >> beginMarker; 404 is >> beginMarker;
417 if (strcmp(beginMarker,"Tausworthe-begin")) 405 if (strcmp(beginMarker,"Tausworthe-begin")) {
418 is.clear(std::ios::badbit | is.rdstate()); 406 is.clear(std::ios::badbit | is.rdstate());
419 std::cerr << "\nInput mispositioned or" 407 std::cerr << "\nInput mispositioned or"
420 << "\nTausworthe state description mis 408 << "\nTausworthe state description missing or"
421 << "\nwrong engine type found." << std 409 << "\nwrong engine type found." << std::endl;
422 } 410 }
423 for (int i = 0; i < 4; ++i) { 411 for (int i = 0; i < 4; ++i) {
424 is >> words[i]; 412 is >> words[i];
425 } 413 }
426 is >> wordIndex; 414 is >> wordIndex;
427 is >> std::ws; 415 is >> std::ws;
428 is.width(MarkerLen); 416 is.width(MarkerLen);
429 is >> endMarker; 417 is >> endMarker;
430 if (strcmp(endMarker,"Tausworthe-end")) { 418 if (strcmp(endMarker,"Tausworthe-end")) {
431 is.clear(std::ios::badbit | is.rdstate()); 419 is.clear(std::ios::badbit | is.rdstate());
432 std::cerr << "\nTausworthe state descripti 420 std::cerr << "\nTausworthe state description incomplete."
433 << "\nInput stream is probably misposi 421 << "\nInput stream is probably mispositioned now." << std::endl;
434 } 422 }
435 } 423 }
436 424
437 bool 425 bool
438 DualRand::Tausworthe::get(std::vector<unsigned 426 DualRand::Tausworthe::get(std::vector<unsigned long>::const_iterator & iv){
439 for (int i = 0; i < 4; ++i) { 427 for (int i = 0; i < 4; ++i) {
440 words[i] = (unsigned int)*iv++; << 428 words[i] = *iv++;
441 } 429 }
442 wordIndex = (int)*iv++; << 430 wordIndex = *iv++;
443 return true; 431 return true;
444 } 432 }
445 433
446 DualRand::IntegerCong::IntegerCong() 434 DualRand::IntegerCong::IntegerCong()
447 : state((unsigned int)3758656018U), 435 : state((unsigned int)3758656018U),
448 multiplier(66565), 436 multiplier(66565),
449 addend(12341) 437 addend(12341)
450 { 438 {
451 } 439 }
452 440
453 DualRand::IntegerCong::IntegerCong(unsigned in 441 DualRand::IntegerCong::IntegerCong(unsigned int seed, int streamNumber)
454 : state(seed), 442 : state(seed),
455 multiplier(65536 + 1024 + 5 + (8 * 1017 * st 443 multiplier(65536 + 1024 + 5 + (8 * 1017 * streamNumber)),
456 addend(12341) 444 addend(12341)
457 { 445 {
458 // As to the multiplier, the following comme 446 // As to the multiplier, the following comment was made:
459 // We want our multipliers larger than 2^16, 447 // We want our multipliers larger than 2^16, and equal to
460 // 1 mod 4 (for max. period), but not equal 448 // 1 mod 4 (for max. period), but not equal to 1 mod 8
461 // (for max. potency -- the smaller and high 449 // (for max. potency -- the smaller and higher dimension the
462 // stripes, the better) 450 // stripes, the better)
463 451
464 // All of these will have fairly long period 452 // All of these will have fairly long periods. Depending on the choice
465 // of stream number, some of these will be q 453 // of stream number, some of these will be quite decent when considered
466 // as independent random engines, while othe 454 // as independent random engines, while others will be poor. Thus these
467 // should not be used as stand-alone engines 455 // should not be used as stand-alone engines; but when combined with a
468 // generator known to be good, they allow cr 456 // generator known to be good, they allow creation of millions of good
469 // independent streams, without fear of two 457 // independent streams, without fear of two streams accidentally hitting
470 // nearby places in the good random sequence 458 // nearby places in the good random sequence.
471 } 459 }
472 460
473 DualRand::IntegerCong::operator unsigned int() 461 DualRand::IntegerCong::operator unsigned int() {
474 return state = (state * multiplier + addend) 462 return state = (state * multiplier + addend) & 0xffffffff;
475 } 463 }
476 464
477 void DualRand::IntegerCong::put(std::ostream & 465 void DualRand::IntegerCong::put(std::ostream & os) const {
478 char beginMarker[] = "IntegerCong-begin"; 466 char beginMarker[] = "IntegerCong-begin";
479 char endMarker[] = "IntegerCong-end"; 467 char endMarker[] = "IntegerCong-end";
480 468
481 long pr=os.precision(20); << 469 int pr=os.precision(20);
482 os << " " << beginMarker << " "; 470 os << " " << beginMarker << " ";
483 os << state << " " << multiplier << " " << a 471 os << state << " " << multiplier << " " << addend;
484 os << " " << endMarker << " "; 472 os << " " << endMarker << " ";
485 os << std::endl; 473 os << std::endl;
486 os.precision(pr); 474 os.precision(pr);
487 } 475 }
488 476
489 void DualRand::IntegerCong::put(std::vector<un 477 void DualRand::IntegerCong::put(std::vector<unsigned long> & v) const {
490 v.push_back(static_cast<unsigned long>(state 478 v.push_back(static_cast<unsigned long>(state));
491 v.push_back(static_cast<unsigned long>(multi 479 v.push_back(static_cast<unsigned long>(multiplier));
492 v.push_back(static_cast<unsigned long>(adden 480 v.push_back(static_cast<unsigned long>(addend));
493 } 481 }
494 482
495 void DualRand::IntegerCong::get(std::istream & 483 void DualRand::IntegerCong::get(std::istream & is) {
496 char beginMarker [MarkerLen]; 484 char beginMarker [MarkerLen];
497 char endMarker [MarkerLen]; 485 char endMarker [MarkerLen];
498 486
499 is >> std::ws; 487 is >> std::ws;
500 is.width(MarkerLen); // causes the next rea 488 is.width(MarkerLen); // causes the next read to the char* to be <=
501 // that many bytes, INCLUDING A TERMINAT 489 // that many bytes, INCLUDING A TERMINATION \0
502 // (Stroustrup, section 21.3.2) 490 // (Stroustrup, section 21.3.2)
503 is >> beginMarker; 491 is >> beginMarker;
504 if (strcmp(beginMarker,"IntegerCong-begin")) 492 if (strcmp(beginMarker,"IntegerCong-begin")) {
505 is.clear(std::ios::badbit | is.rdstate()); 493 is.clear(std::ios::badbit | is.rdstate());
506 std::cerr << "\nInput mispositioned or" 494 std::cerr << "\nInput mispositioned or"
507 << "\nIntegerCong state description mi 495 << "\nIntegerCong state description missing or"
508 << "\nwrong engine type found." << std 496 << "\nwrong engine type found." << std::endl;
509 } 497 }
510 is >> state >> multiplier >> addend; 498 is >> state >> multiplier >> addend;
511 is >> std::ws; 499 is >> std::ws;
512 is.width(MarkerLen); 500 is.width(MarkerLen);
513 is >> endMarker; 501 is >> endMarker;
514 if (strcmp(endMarker,"IntegerCong-end")) { 502 if (strcmp(endMarker,"IntegerCong-end")) {
515 is.clear(std::ios::badbit | is.rdstate()); 503 is.clear(std::ios::badbit | is.rdstate());
516 std::cerr << "\nIntegerCong state descript 504 std::cerr << "\nIntegerCong state description incomplete."
517 << "\nInput stream is probably misposi 505 << "\nInput stream is probably mispositioned now." << std::endl;
518 } 506 }
519 } 507 }
520 508
521 bool 509 bool
522 DualRand::IntegerCong::get(std::vector<unsigne 510 DualRand::IntegerCong::get(std::vector<unsigned long>::const_iterator & iv) {
523 state = (unsigned int)*iv++; << 511 state = *iv++;
524 multiplier = (unsigned int)*iv++; << 512 multiplier = *iv++;
525 addend = (unsigned int)*iv++; << 513 addend = *iv++;
526 return true; 514 return true;
527 } 515 }
528 516
529 } // namespace CLHEP 517 } // namespace CLHEP
530 518