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1 // random number generation -*- C++ -*- | |
2 | |
3 // Copyright (C) 2007, 2008, 2009 Free Software Foundation, Inc. | |
4 // | |
5 // This file is part of the GNU ISO C++ Library. This library is free | |
6 // software; you can redistribute it and/or modify it under the | |
7 // terms of the GNU General Public License as published by the | |
8 // Free Software Foundation; either version 3, or (at your option) | |
9 // any later version. | |
10 | |
11 // This library is distributed in the hope that it will be useful, | |
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 // GNU General Public License for more details. | |
15 | |
16 // Under Section 7 of GPL version 3, you are granted additional | |
17 // permissions described in the GCC Runtime Library Exception, version | |
18 // 3.1, as published by the Free Software Foundation. | |
19 | |
20 // You should have received a copy of the GNU General Public License and | |
21 // a copy of the GCC Runtime Library Exception along with this program; | |
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
23 // <http://www.gnu.org/licenses/>. | |
24 | |
25 /** | |
26 * @file tr1_impl/random | |
27 * This is an internal header file, included by other library headers. | |
28 * You should not attempt to use it directly. | |
29 */ | |
30 | |
31 namespace std | |
32 { | |
33 _GLIBCXX_BEGIN_NAMESPACE_TR1 | |
34 | |
35 // [5.1] Random number generation | |
36 | |
37 /** | |
38 * @defgroup tr1_random Random Number Generation | |
39 * @ingroup numerics | |
40 * A facility for generating random numbers on selected distributions. | |
41 * @{ | |
42 */ | |
43 | |
44 /* | |
45 * Implementation-space details. | |
46 */ | |
47 namespace __detail | |
48 { | |
49 template<typename _UIntType, int __w, | |
50 bool = __w < std::numeric_limits<_UIntType>::digits> | |
51 struct _Shift | |
52 { static const _UIntType __value = 0; }; | |
53 | |
54 template<typename _UIntType, int __w> | |
55 struct _Shift<_UIntType, __w, true> | |
56 { static const _UIntType __value = _UIntType(1) << __w; }; | |
57 | |
58 template<typename _Tp, _Tp __a, _Tp __c, _Tp __m, bool> | |
59 struct _Mod; | |
60 | |
61 // Dispatch based on modulus value to prevent divide-by-zero compile-time | |
62 // errors when m == 0. | |
63 template<typename _Tp, _Tp __a, _Tp __c, _Tp __m> | |
64 inline _Tp | |
65 __mod(_Tp __x) | |
66 { return _Mod<_Tp, __a, __c, __m, __m == 0>::__calc(__x); } | |
67 | |
68 typedef __gnu_cxx::__conditional_type<(sizeof(unsigned) == 4), | |
69 unsigned, unsigned long>::__type _UInt32Type; | |
70 | |
71 /* | |
72 * An adaptor class for converting the output of any Generator into | |
73 * the input for a specific Distribution. | |
74 */ | |
75 template<typename _Engine, typename _Distribution> | |
76 struct _Adaptor | |
77 { | |
78 typedef typename remove_reference<_Engine>::type _BEngine; | |
79 typedef typename _BEngine::result_type _Engine_result_type; | |
80 typedef typename _Distribution::input_type result_type; | |
81 | |
82 public: | |
83 _Adaptor(const _Engine& __g) | |
84 : _M_g(__g) { } | |
85 | |
86 result_type | |
87 min() const | |
88 { | |
89 result_type __return_value; | |
90 if (is_integral<_Engine_result_type>::value | |
91 && is_integral<result_type>::value) | |
92 __return_value = _M_g.min(); | |
93 else | |
94 __return_value = result_type(0); | |
95 return __return_value; | |
96 } | |
97 | |
98 result_type | |
99 max() const | |
100 { | |
101 result_type __return_value; | |
102 if (is_integral<_Engine_result_type>::value | |
103 && is_integral<result_type>::value) | |
104 __return_value = _M_g.max(); | |
105 else if (!is_integral<result_type>::value) | |
106 __return_value = result_type(1); | |
107 else | |
108 __return_value = std::numeric_limits<result_type>::max() - 1; | |
109 return __return_value; | |
110 } | |
111 | |
112 /* | |
113 * Converts a value generated by the adapted random number generator | |
114 * into a value in the input domain for the dependent random number | |
115 * distribution. | |
116 * | |
117 * Because the type traits are compile time constants only the | |
118 * appropriate clause of the if statements will actually be emitted | |
119 * by the compiler. | |
120 */ | |
121 result_type | |
122 operator()() | |
123 { | |
124 result_type __return_value; | |
125 if (is_integral<_Engine_result_type>::value | |
126 && is_integral<result_type>::value) | |
127 __return_value = _M_g(); | |
128 else if (!is_integral<_Engine_result_type>::value | |
129 && !is_integral<result_type>::value) | |
130 __return_value = result_type(_M_g() - _M_g.min()) | |
131 / result_type(_M_g.max() - _M_g.min()); | |
132 else if (is_integral<_Engine_result_type>::value | |
133 && !is_integral<result_type>::value) | |
134 __return_value = result_type(_M_g() - _M_g.min()) | |
135 / result_type(_M_g.max() - _M_g.min() + result_type(1)); | |
136 else | |
137 __return_value = (((_M_g() - _M_g.min()) | |
138 / (_M_g.max() - _M_g.min())) | |
139 * std::numeric_limits<result_type>::max()); | |
140 return __return_value; | |
141 } | |
142 | |
143 private: | |
144 _Engine _M_g; | |
145 }; | |
146 | |
147 // Specialization for _Engine*. | |
148 template<typename _Engine, typename _Distribution> | |
149 struct _Adaptor<_Engine*, _Distribution> | |
150 { | |
151 typedef typename _Engine::result_type _Engine_result_type; | |
152 typedef typename _Distribution::input_type result_type; | |
153 | |
154 public: | |
155 _Adaptor(_Engine* __g) | |
156 : _M_g(__g) { } | |
157 | |
158 result_type | |
159 min() const | |
160 { | |
161 result_type __return_value; | |
162 if (is_integral<_Engine_result_type>::value | |
163 && is_integral<result_type>::value) | |
164 __return_value = _M_g->min(); | |
165 else | |
166 __return_value = result_type(0); | |
167 return __return_value; | |
168 } | |
169 | |
170 result_type | |
171 max() const | |
172 { | |
173 result_type __return_value; | |
174 if (is_integral<_Engine_result_type>::value | |
175 && is_integral<result_type>::value) | |
176 __return_value = _M_g->max(); | |
177 else if (!is_integral<result_type>::value) | |
178 __return_value = result_type(1); | |
179 else | |
180 __return_value = std::numeric_limits<result_type>::max() - 1; | |
181 return __return_value; | |
182 } | |
183 | |
184 result_type | |
185 operator()() | |
186 { | |
187 result_type __return_value; | |
188 if (is_integral<_Engine_result_type>::value | |
189 && is_integral<result_type>::value) | |
190 __return_value = (*_M_g)(); | |
191 else if (!is_integral<_Engine_result_type>::value | |
192 && !is_integral<result_type>::value) | |
193 __return_value = result_type((*_M_g)() - _M_g->min()) | |
194 / result_type(_M_g->max() - _M_g->min()); | |
195 else if (is_integral<_Engine_result_type>::value | |
196 && !is_integral<result_type>::value) | |
197 __return_value = result_type((*_M_g)() - _M_g->min()) | |
198 / result_type(_M_g->max() - _M_g->min() + result_type(1)); | |
199 else | |
200 __return_value = ((((*_M_g)() - _M_g->min()) | |
201 / (_M_g->max() - _M_g->min())) | |
202 * std::numeric_limits<result_type>::max()); | |
203 return __return_value; | |
204 } | |
205 | |
206 private: | |
207 _Engine* _M_g; | |
208 }; | |
209 } // namespace __detail | |
210 | |
211 /** | |
212 * Produces random numbers on a given distribution function using a | |
213 * non-uniform random number generation engine. | |
214 * | |
215 * @todo the engine_value_type needs to be studied more carefully. | |
216 */ | |
217 template<typename _Engine, typename _Dist> | |
218 class variate_generator | |
219 { | |
220 // Concept requirements. | |
221 __glibcxx_class_requires(_Engine, _CopyConstructibleConcept) | |
222 // __glibcxx_class_requires(_Engine, _EngineConcept) | |
223 // __glibcxx_class_requires(_Dist, _EngineConcept) | |
224 | |
225 public: | |
226 typedef _Engine engine_type; | |
227 typedef __detail::_Adaptor<_Engine, _Dist> engine_value_type; | |
228 typedef _Dist distribution_type; | |
229 typedef typename _Dist::result_type result_type; | |
230 | |
231 // tr1:5.1.1 table 5.1 requirement | |
232 typedef typename __gnu_cxx::__enable_if< | |
233 is_arithmetic<result_type>::value, result_type>::__type _IsValidType; | |
234 | |
235 /** | |
236 * Constructs a variate generator with the uniform random number | |
237 * generator @p __eng for the random distribution @p __dist. | |
238 * | |
239 * @throws Any exceptions which may thrown by the copy constructors of | |
240 * the @p _Engine or @p _Dist objects. | |
241 */ | |
242 variate_generator(engine_type __eng, distribution_type __dist) | |
243 : _M_engine(__eng), _M_dist(__dist) { } | |
244 | |
245 /** | |
246 * Gets the next generated value on the distribution. | |
247 */ | |
248 result_type | |
249 operator()() | |
250 { return _M_dist(_M_engine); } | |
251 | |
252 /** | |
253 * WTF? | |
254 */ | |
255 template<typename _Tp> | |
256 result_type | |
257 operator()(_Tp __value) | |
258 { return _M_dist(_M_engine, __value); } | |
259 | |
260 /** | |
261 * Gets a reference to the underlying uniform random number generator | |
262 * object. | |
263 */ | |
264 engine_value_type& | |
265 engine() | |
266 { return _M_engine; } | |
267 | |
268 /** | |
269 * Gets a const reference to the underlying uniform random number | |
270 * generator object. | |
271 */ | |
272 const engine_value_type& | |
273 engine() const | |
274 { return _M_engine; } | |
275 | |
276 /** | |
277 * Gets a reference to the underlying random distribution. | |
278 */ | |
279 distribution_type& | |
280 distribution() | |
281 { return _M_dist; } | |
282 | |
283 /** | |
284 * Gets a const reference to the underlying random distribution. | |
285 */ | |
286 const distribution_type& | |
287 distribution() const | |
288 { return _M_dist; } | |
289 | |
290 /** | |
291 * Gets the closed lower bound of the distribution interval. | |
292 */ | |
293 result_type | |
294 min() const | |
295 { return this->distribution().min(); } | |
296 | |
297 /** | |
298 * Gets the closed upper bound of the distribution interval. | |
299 */ | |
300 result_type | |
301 max() const | |
302 { return this->distribution().max(); } | |
303 | |
304 private: | |
305 engine_value_type _M_engine; | |
306 distribution_type _M_dist; | |
307 }; | |
308 | |
309 | |
310 /** | |
311 * @defgroup tr1_random_generators Random Number Generators | |
312 * @ingroup tr1_random | |
313 * | |
314 * These classes define objects which provide random or pseudorandom | |
315 * numbers, either from a discrete or a continuous interval. The | |
316 * random number generator supplied as a part of this library are | |
317 * all uniform random number generators which provide a sequence of | |
318 * random number uniformly distributed over their range. | |
319 * | |
320 * A number generator is a function object with an operator() that | |
321 * takes zero arguments and returns a number. | |
322 * | |
323 * A compliant random number generator must satisfy the following | |
324 * requirements. <table border=1 cellpadding=10 cellspacing=0> | |
325 * <caption align=top>Random Number Generator Requirements</caption> | |
326 * <tr><td>To be documented.</td></tr> </table> | |
327 * | |
328 * @{ | |
329 */ | |
330 | |
331 /** | |
332 * @brief A model of a linear congruential random number generator. | |
333 * | |
334 * A random number generator that produces pseudorandom numbers using the | |
335 * linear function @f$x_{i+1}\leftarrow(ax_{i} + c) \bmod m @f$. | |
336 * | |
337 * The template parameter @p _UIntType must be an unsigned integral type | |
338 * large enough to store values up to (__m-1). If the template parameter | |
339 * @p __m is 0, the modulus @p __m used is | |
340 * std::numeric_limits<_UIntType>::max() plus 1. Otherwise, the template | |
341 * parameters @p __a and @p __c must be less than @p __m. | |
342 * | |
343 * The size of the state is @f$ 1 @f$. | |
344 */ | |
345 template<class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> | |
346 class linear_congruential | |
347 { | |
348 __glibcxx_class_requires(_UIntType, _UnsignedIntegerConcept) | |
349 // __glibcpp_class_requires(__a < __m && __c < __m) | |
350 | |
351 public: | |
352 /** The type of the generated random value. */ | |
353 typedef _UIntType result_type; | |
354 | |
355 /** The multiplier. */ | |
356 static const _UIntType multiplier = __a; | |
357 /** An increment. */ | |
358 static const _UIntType increment = __c; | |
359 /** The modulus. */ | |
360 static const _UIntType modulus = __m; | |
361 | |
362 /** | |
363 * Constructs a %linear_congruential random number generator engine with | |
364 * seed @p __s. The default seed value is 1. | |
365 * | |
366 * @param __s The initial seed value. | |
367 */ | |
368 explicit | |
369 linear_congruential(unsigned long __x0 = 1) | |
370 { this->seed(__x0); } | |
371 | |
372 /** | |
373 * Constructs a %linear_congruential random number generator engine | |
374 * seeded from the generator function @p __g. | |
375 * | |
376 * @param __g The seed generator function. | |
377 */ | |
378 template<class _Gen> | |
379 linear_congruential(_Gen& __g) | |
380 { this->seed(__g); } | |
381 | |
382 /** | |
383 * Reseeds the %linear_congruential random number generator engine | |
384 * sequence to the seed @g __s. | |
385 * | |
386 * @param __s The new seed. | |
387 */ | |
388 void | |
389 seed(unsigned long __s = 1); | |
390 | |
391 /** | |
392 * Reseeds the %linear_congruential random number generator engine | |
393 * sequence using values from the generator function @p __g. | |
394 * | |
395 * @param __g the seed generator function. | |
396 */ | |
397 template<class _Gen> | |
398 void | |
399 seed(_Gen& __g) | |
400 { seed(__g, typename is_fundamental<_Gen>::type()); } | |
401 | |
402 /** | |
403 * Gets the smallest possible value in the output range. | |
404 * | |
405 * The minimum depends on the @p __c parameter: if it is zero, the | |
406 * minimum generated must be > 0, otherwise 0 is allowed. | |
407 */ | |
408 result_type | |
409 min() const | |
410 { return (__detail::__mod<_UIntType, 1, 0, __m>(__c) == 0) ? 1 : 0; } | |
411 | |
412 /** | |
413 * Gets the largest possible value in the output range. | |
414 */ | |
415 result_type | |
416 max() const | |
417 { return __m - 1; } | |
418 | |
419 /** | |
420 * Gets the next random number in the sequence. | |
421 */ | |
422 result_type | |
423 operator()(); | |
424 | |
425 /** | |
426 * Compares two linear congruential random number generator | |
427 * objects of the same type for equality. | |
428 * | |
429 * @param __lhs A linear congruential random number generator object. | |
430 * @param __rhs Another linear congruential random number generator obj. | |
431 * | |
432 * @returns true if the two objects are equal, false otherwise. | |
433 */ | |
434 friend bool | |
435 operator==(const linear_congruential& __lhs, | |
436 const linear_congruential& __rhs) | |
437 { return __lhs._M_x == __rhs._M_x; } | |
438 | |
439 /** | |
440 * Compares two linear congruential random number generator | |
441 * objects of the same type for inequality. | |
442 * | |
443 * @param __lhs A linear congruential random number generator object. | |
444 * @param __rhs Another linear congruential random number generator obj. | |
445 * | |
446 * @returns true if the two objects are not equal, false otherwise. | |
447 */ | |
448 friend bool | |
449 operator!=(const linear_congruential& __lhs, | |
450 const linear_congruential& __rhs) | |
451 { return !(__lhs == __rhs); } | |
452 | |
453 /** | |
454 * Writes the textual representation of the state x(i) of x to @p __os. | |
455 * | |
456 * @param __os The output stream. | |
457 * @param __lcr A % linear_congruential random number generator. | |
458 * @returns __os. | |
459 */ | |
460 template<class _UIntType1, _UIntType1 __a1, _UIntType1 __c1, | |
461 _UIntType1 __m1, | |
462 typename _CharT, typename _Traits> | |
463 friend std::basic_ostream<_CharT, _Traits>& | |
464 operator<<(std::basic_ostream<_CharT, _Traits>& __os, | |
465 const linear_congruential<_UIntType1, __a1, __c1, | |
466 __m1>& __lcr); | |
467 | |
468 /** | |
469 * Sets the state of the engine by reading its textual | |
470 * representation from @p __is. | |
471 * | |
472 * The textual representation must have been previously written using an | |
473 * output stream whose imbued locale and whose type's template | |
474 * specialization arguments _CharT and _Traits were the same as those of | |
475 * @p __is. | |
476 * | |
477 * @param __is The input stream. | |
478 * @param __lcr A % linear_congruential random number generator. | |
479 * @returns __is. | |
480 */ | |
481 template<class _UIntType1, _UIntType1 __a1, _UIntType1 __c1, | |
482 _UIntType1 __m1, | |
483 typename _CharT, typename _Traits> | |
484 friend std::basic_istream<_CharT, _Traits>& | |
485 operator>>(std::basic_istream<_CharT, _Traits>& __is, | |
486 linear_congruential<_UIntType1, __a1, __c1, __m1>& __lcr); | |
487 | |
488 private: | |
489 template<class _Gen> | |
490 void | |
491 seed(_Gen& __g, true_type) | |
492 { return seed(static_cast<unsigned long>(__g)); } | |
493 | |
494 template<class _Gen> | |
495 void | |
496 seed(_Gen& __g, false_type); | |
497 | |
498 _UIntType _M_x; | |
499 }; | |
500 | |
501 /** | |
502 * The classic Minimum Standard rand0 of Lewis, Goodman, and Miller. | |
503 */ | |
504 typedef linear_congruential<unsigned long, 16807, 0, 2147483647> minstd_rand0; | |
505 | |
506 /** | |
507 * An alternative LCR (Lehmer Generator function) . | |
508 */ | |
509 typedef linear_congruential<unsigned long, 48271, 0, 2147483647> minstd_rand; | |
510 | |
511 | |
512 /** | |
513 * A generalized feedback shift register discrete random number generator. | |
514 * | |
515 * This algorithm avoids multiplication and division and is designed to be | |
516 * friendly to a pipelined architecture. If the parameters are chosen | |
517 * correctly, this generator will produce numbers with a very long period and | |
518 * fairly good apparent entropy, although still not cryptographically strong. | |
519 * | |
520 * The best way to use this generator is with the predefined mt19937 class. | |
521 * | |
522 * This algorithm was originally invented by Makoto Matsumoto and | |
523 * Takuji Nishimura. | |
524 * | |
525 * @var word_size The number of bits in each element of the state vector. | |
526 * @var state_size The degree of recursion. | |
527 * @var shift_size The period parameter. | |
528 * @var mask_bits The separation point bit index. | |
529 * @var parameter_a The last row of the twist matrix. | |
530 * @var output_u The first right-shift tempering matrix parameter. | |
531 * @var output_s The first left-shift tempering matrix parameter. | |
532 * @var output_b The first left-shift tempering matrix mask. | |
533 * @var output_t The second left-shift tempering matrix parameter. | |
534 * @var output_c The second left-shift tempering matrix mask. | |
535 * @var output_l The second right-shift tempering matrix parameter. | |
536 */ | |
537 template<class _UIntType, int __w, int __n, int __m, int __r, | |
538 _UIntType __a, int __u, int __s, _UIntType __b, int __t, | |
539 _UIntType __c, int __l> | |
540 class mersenne_twister | |
541 { | |
542 __glibcxx_class_requires(_UIntType, _UnsignedIntegerConcept) | |
543 | |
544 public: | |
545 // types | |
546 typedef _UIntType result_type; | |
547 | |
548 // parameter values | |
549 static const int word_size = __w; | |
550 static const int state_size = __n; | |
551 static const int shift_size = __m; | |
552 static const int mask_bits = __r; | |
553 static const _UIntType parameter_a = __a; | |
554 static const int output_u = __u; | |
555 static const int output_s = __s; | |
556 static const _UIntType output_b = __b; | |
557 static const int output_t = __t; | |
558 static const _UIntType output_c = __c; | |
559 static const int output_l = __l; | |
560 | |
561 // constructors and member function | |
562 mersenne_twister() | |
563 { seed(); } | |
564 | |
565 explicit | |
566 mersenne_twister(unsigned long __value) | |
567 { seed(__value); } | |
568 | |
569 template<class _Gen> | |
570 mersenne_twister(_Gen& __g) | |
571 { seed(__g); } | |
572 | |
573 void | |
574 seed() | |
575 { seed(5489UL); } | |
576 | |
577 void | |
578 seed(unsigned long __value); | |
579 | |
580 template<class _Gen> | |
581 void | |
582 seed(_Gen& __g) | |
583 { seed(__g, typename is_fundamental<_Gen>::type()); } | |
584 | |
585 result_type | |
586 min() const | |
587 { return 0; }; | |
588 | |
589 result_type | |
590 max() const | |
591 { return __detail::_Shift<_UIntType, __w>::__value - 1; } | |
592 | |
593 result_type | |
594 operator()(); | |
595 | |
596 /** | |
597 * Compares two % mersenne_twister random number generator objects of | |
598 * the same type for equality. | |
599 * | |
600 * @param __lhs A % mersenne_twister random number generator object. | |
601 * @param __rhs Another % mersenne_twister random number generator | |
602 * object. | |
603 * | |
604 * @returns true if the two objects are equal, false otherwise. | |
605 */ | |
606 friend bool | |
607 operator==(const mersenne_twister& __lhs, | |
608 const mersenne_twister& __rhs) | |
609 { return std::equal(__lhs._M_x, __lhs._M_x + state_size, __rhs._M_x); } | |
610 | |
611 /** | |
612 * Compares two % mersenne_twister random number generator objects of | |
613 * the same type for inequality. | |
614 * | |
615 * @param __lhs A % mersenne_twister random number generator object. | |
616 * @param __rhs Another % mersenne_twister random number generator | |
617 * object. | |
618 * | |
619 * @returns true if the two objects are not equal, false otherwise. | |
620 */ | |
621 friend bool | |
622 operator!=(const mersenne_twister& __lhs, | |
623 const mersenne_twister& __rhs) | |
624 { return !(__lhs == __rhs); } | |
625 | |
626 /** | |
627 * Inserts the current state of a % mersenne_twister random number | |
628 * generator engine @p __x into the output stream @p __os. | |
629 * | |
630 * @param __os An output stream. | |
631 * @param __x A % mersenne_twister random number generator engine. | |
632 * | |
633 * @returns The output stream with the state of @p __x inserted or in | |
634 * an error state. | |
635 */ | |
636 template<class _UIntType1, int __w1, int __n1, int __m1, int __r1, | |
637 _UIntType1 __a1, int __u1, int __s1, _UIntType1 __b1, int __t1, | |
638 _UIntType1 __c1, int __l1, | |
639 typename _CharT, typename _Traits> | |
640 friend std::basic_ostream<_CharT, _Traits>& | |
641 operator<<(std::basic_ostream<_CharT, _Traits>& __os, | |
642 const mersenne_twister<_UIntType1, __w1, __n1, __m1, __r1, | |
643 __a1, __u1, __s1, __b1, __t1, __c1, __l1>& __x); | |
644 | |
645 /** | |
646 * Extracts the current state of a % mersenne_twister random number | |
647 * generator engine @p __x from the input stream @p __is. | |
648 * | |
649 * @param __is An input stream. | |
650 * @param __x A % mersenne_twister random number generator engine. | |
651 * | |
652 * @returns The input stream with the state of @p __x extracted or in | |
653 * an error state. | |
654 */ | |
655 template<class _UIntType1, int __w1, int __n1, int __m1, int __r1, | |
656 _UIntType1 __a1, int __u1, int __s1, _UIntType1 __b1, int __t1, | |
657 _UIntType1 __c1, int __l1, | |
658 typename _CharT, typename _Traits> | |
659 friend std::basic_istream<_CharT, _Traits>& | |
660 operator>>(std::basic_istream<_CharT, _Traits>& __is, | |
661 mersenne_twister<_UIntType1, __w1, __n1, __m1, __r1, | |
662 __a1, __u1, __s1, __b1, __t1, __c1, __l1>& __x); | |
663 | |
664 private: | |
665 template<class _Gen> | |
666 void | |
667 seed(_Gen& __g, true_type) | |
668 { return seed(static_cast<unsigned long>(__g)); } | |
669 | |
670 template<class _Gen> | |
671 void | |
672 seed(_Gen& __g, false_type); | |
673 | |
674 _UIntType _M_x[state_size]; | |
675 int _M_p; | |
676 }; | |
677 | |
678 /** | |
679 * The classic Mersenne Twister. | |
680 * | |
681 * Reference: | |
682 * M. Matsumoto and T. Nishimura, "Mersenne Twister: A 623-Dimensionally | |
683 * Equidistributed Uniform Pseudo-Random Number Generator", ACM Transactions | |
684 * on Modeling and Computer Simulation, Vol. 8, No. 1, January 1998, pp 3-30. | |
685 */ | |
686 typedef mersenne_twister< | |
687 unsigned long, 32, 624, 397, 31, | |
688 0x9908b0dful, 11, 7, | |
689 0x9d2c5680ul, 15, | |
690 0xefc60000ul, 18 | |
691 > mt19937; | |
692 | |
693 | |
694 /** | |
695 * @brief The Marsaglia-Zaman generator. | |
696 * | |
697 * This is a model of a Generalized Fibonacci discrete random number | |
698 * generator, sometimes referred to as the SWC generator. | |
699 * | |
700 * A discrete random number generator that produces pseudorandom | |
701 * numbers using @f$x_{i}\leftarrow(x_{i - s} - x_{i - r} - | |
702 * carry_{i-1}) \bmod m @f$. | |
703 * | |
704 * The size of the state is @f$ r @f$ | |
705 * and the maximum period of the generator is @f$ m^r - m^s -1 @f$. | |
706 * | |
707 * N1688[4.13] says "the template parameter _IntType shall denote an integral | |
708 * type large enough to store values up to m." | |
709 * | |
710 * @var _M_x The state of the generator. This is a ring buffer. | |
711 * @var _M_carry The carry. | |
712 * @var _M_p Current index of x(i - r). | |
713 */ | |
714 template<typename _IntType, _IntType __m, int __s, int __r> | |
715 class subtract_with_carry | |
716 { | |
717 __glibcxx_class_requires(_IntType, _IntegerConcept) | |
718 | |
719 public: | |
720 /** The type of the generated random value. */ | |
721 typedef _IntType result_type; | |
722 | |
723 // parameter values | |
724 static const _IntType modulus = __m; | |
725 static const int long_lag = __r; | |
726 static const int short_lag = __s; | |
727 | |
728 /** | |
729 * Constructs a default-initialized % subtract_with_carry random number | |
730 * generator. | |
731 */ | |
732 subtract_with_carry() | |
733 { this->seed(); } | |
734 | |
735 /** | |
736 * Constructs an explicitly seeded % subtract_with_carry random number | |
737 * generator. | |
738 */ | |
739 explicit | |
740 subtract_with_carry(unsigned long __value) | |
741 { this->seed(__value); } | |
742 | |
743 /** | |
744 * Constructs a %subtract_with_carry random number generator engine | |
745 * seeded from the generator function @p __g. | |
746 * | |
747 * @param __g The seed generator function. | |
748 */ | |
749 template<class _Gen> | |
750 subtract_with_carry(_Gen& __g) | |
751 { this->seed(__g); } | |
752 | |
753 /** | |
754 * Seeds the initial state @f$ x_0 @f$ of the random number generator. | |
755 * | |
756 * N1688[4.19] modifies this as follows. If @p __value == 0, | |
757 * sets value to 19780503. In any case, with a linear | |
758 * congruential generator lcg(i) having parameters @f$ m_{lcg} = | |
759 * 2147483563, a_{lcg} = 40014, c_{lcg} = 0, and lcg(0) = value | |
760 * @f$, sets @f$ x_{-r} \dots x_{-1} @f$ to @f$ lcg(1) \bmod m | |
761 * \dots lcg(r) \bmod m @f$ respectively. If @f$ x_{-1} = 0 @f$ | |
762 * set carry to 1, otherwise sets carry to 0. | |
763 */ | |
764 void | |
765 seed(unsigned long __value = 19780503); | |
766 | |
767 /** | |
768 * Seeds the initial state @f$ x_0 @f$ of the % subtract_with_carry | |
769 * random number generator. | |
770 */ | |
771 template<class _Gen> | |
772 void | |
773 seed(_Gen& __g) | |
774 { seed(__g, typename is_fundamental<_Gen>::type()); } | |
775 | |
776 /** | |
777 * Gets the inclusive minimum value of the range of random integers | |
778 * returned by this generator. | |
779 */ | |
780 result_type | |
781 min() const | |
782 { return 0; } | |
783 | |
784 /** | |
785 * Gets the inclusive maximum value of the range of random integers | |
786 * returned by this generator. | |
787 */ | |
788 result_type | |
789 max() const | |
790 { return this->modulus - 1; } | |
791 | |
792 /** | |
793 * Gets the next random number in the sequence. | |
794 */ | |
795 result_type | |
796 operator()(); | |
797 | |
798 /** | |
799 * Compares two % subtract_with_carry random number generator objects of | |
800 * the same type for equality. | |
801 * | |
802 * @param __lhs A % subtract_with_carry random number generator object. | |
803 * @param __rhs Another % subtract_with_carry random number generator | |
804 * object. | |
805 * | |
806 * @returns true if the two objects are equal, false otherwise. | |
807 */ | |
808 friend bool | |
809 operator==(const subtract_with_carry& __lhs, | |
810 const subtract_with_carry& __rhs) | |
811 { return std::equal(__lhs._M_x, __lhs._M_x + long_lag, __rhs._M_x); } | |
812 | |
813 /** | |
814 * Compares two % subtract_with_carry random number generator objects of | |
815 * the same type for inequality. | |
816 * | |
817 * @param __lhs A % subtract_with_carry random number generator object. | |
818 * @param __rhs Another % subtract_with_carry random number generator | |
819 * object. | |
820 * | |
821 * @returns true if the two objects are not equal, false otherwise. | |
822 */ | |
823 friend bool | |
824 operator!=(const subtract_with_carry& __lhs, | |
825 const subtract_with_carry& __rhs) | |
826 { return !(__lhs == __rhs); } | |
827 | |
828 /** | |
829 * Inserts the current state of a % subtract_with_carry random number | |
830 * generator engine @p __x into the output stream @p __os. | |
831 * | |
832 * @param __os An output stream. | |
833 * @param __x A % subtract_with_carry random number generator engine. | |
834 * | |
835 * @returns The output stream with the state of @p __x inserted or in | |
836 * an error state. | |
837 */ | |
838 template<typename _IntType1, _IntType1 __m1, int __s1, int __r1, | |
839 typename _CharT, typename _Traits> | |
840 friend std::basic_ostream<_CharT, _Traits>& | |
841 operator<<(std::basic_ostream<_CharT, _Traits>& __os, | |
842 const subtract_with_carry<_IntType1, __m1, __s1, | |
843 __r1>& __x); | |
844 | |
845 /** | |
846 * Extracts the current state of a % subtract_with_carry random number | |
847 * generator engine @p __x from the input stream @p __is. | |
848 * | |
849 * @param __is An input stream. | |
850 * @param __x A % subtract_with_carry random number generator engine. | |
851 * | |
852 * @returns The input stream with the state of @p __x extracted or in | |
853 * an error state. | |
854 */ | |
855 template<typename _IntType1, _IntType1 __m1, int __s1, int __r1, | |
856 typename _CharT, typename _Traits> | |
857 friend std::basic_istream<_CharT, _Traits>& | |
858 operator>>(std::basic_istream<_CharT, _Traits>& __is, | |
859 subtract_with_carry<_IntType1, __m1, __s1, __r1>& __x); | |
860 | |
861 private: | |
862 template<class _Gen> | |
863 void | |
864 seed(_Gen& __g, true_type) | |
865 { return seed(static_cast<unsigned long>(__g)); } | |
866 | |
867 template<class _Gen> | |
868 void | |
869 seed(_Gen& __g, false_type); | |
870 | |
871 typedef typename __gnu_cxx::__add_unsigned<_IntType>::__type _UIntType; | |
872 | |
873 _UIntType _M_x[long_lag]; | |
874 _UIntType _M_carry; | |
875 int _M_p; | |
876 }; | |
877 | |
878 | |
879 /** | |
880 * @brief The Marsaglia-Zaman generator (floats version). | |
881 * | |
882 * @var _M_x The state of the generator. This is a ring buffer. | |
883 * @var _M_carry The carry. | |
884 * @var _M_p Current index of x(i - r). | |
885 * @var _M_npows Precomputed negative powers of 2. | |
886 */ | |
887 template<typename _RealType, int __w, int __s, int __r> | |
888 class subtract_with_carry_01 | |
889 { | |
890 public: | |
891 /** The type of the generated random value. */ | |
892 typedef _RealType result_type; | |
893 | |
894 // parameter values | |
895 static const int word_size = __w; | |
896 static const int long_lag = __r; | |
897 static const int short_lag = __s; | |
898 | |
899 /** | |
900 * Constructs a default-initialized % subtract_with_carry_01 random | |
901 * number generator. | |
902 */ | |
903 subtract_with_carry_01() | |
904 { | |
905 this->seed(); | |
906 _M_initialize_npows(); | |
907 } | |
908 | |
909 /** | |
910 * Constructs an explicitly seeded % subtract_with_carry_01 random number | |
911 * generator. | |
912 */ | |
913 explicit | |
914 subtract_with_carry_01(unsigned long __value) | |
915 { | |
916 this->seed(__value); | |
917 _M_initialize_npows(); | |
918 } | |
919 | |
920 /** | |
921 * Constructs a % subtract_with_carry_01 random number generator engine | |
922 * seeded from the generator function @p __g. | |
923 * | |
924 * @param __g The seed generator function. | |
925 */ | |
926 template<class _Gen> | |
927 subtract_with_carry_01(_Gen& __g) | |
928 { | |
929 this->seed(__g); | |
930 _M_initialize_npows(); | |
931 } | |
932 | |
933 /** | |
934 * Seeds the initial state @f$ x_0 @f$ of the random number generator. | |
935 */ | |
936 void | |
937 seed(unsigned long __value = 19780503); | |
938 | |
939 /** | |
940 * Seeds the initial state @f$ x_0 @f$ of the % subtract_with_carry_01 | |
941 * random number generator. | |
942 */ | |
943 template<class _Gen> | |
944 void | |
945 seed(_Gen& __g) | |
946 { seed(__g, typename is_fundamental<_Gen>::type()); } | |
947 | |
948 /** | |
949 * Gets the minimum value of the range of random floats | |
950 * returned by this generator. | |
951 */ | |
952 result_type | |
953 min() const | |
954 { return 0.0; } | |
955 | |
956 /** | |
957 * Gets the maximum value of the range of random floats | |
958 * returned by this generator. | |
959 */ | |
960 result_type | |
961 max() const | |
962 { return 1.0; } | |
963 | |
964 /** | |
965 * Gets the next random number in the sequence. | |
966 */ | |
967 result_type | |
968 operator()(); | |
969 | |
970 /** | |
971 * Compares two % subtract_with_carry_01 random number generator objects | |
972 * of the same type for equality. | |
973 * | |
974 * @param __lhs A % subtract_with_carry_01 random number | |
975 * generator object. | |
976 * @param __rhs Another % subtract_with_carry_01 random number generator | |
977 * object. | |
978 * | |
979 * @returns true if the two objects are equal, false otherwise. | |
980 */ | |
981 friend bool | |
982 operator==(const subtract_with_carry_01& __lhs, | |
983 const subtract_with_carry_01& __rhs) | |
984 { | |
985 for (int __i = 0; __i < long_lag; ++__i) | |
986 if (!std::equal(__lhs._M_x[__i], __lhs._M_x[__i] + __n, | |
987 __rhs._M_x[__i])) | |
988 return false; | |
989 return true; | |
990 } | |
991 | |
992 /** | |
993 * Compares two % subtract_with_carry_01 random number generator objects | |
994 * of the same type for inequality. | |
995 * | |
996 * @param __lhs A % subtract_with_carry_01 random number | |
997 * generator object. | |
998 * | |
999 * @param __rhs Another % subtract_with_carry_01 random number generator | |
1000 * object. | |
1001 * | |
1002 * @returns true if the two objects are not equal, false otherwise. | |
1003 */ | |
1004 friend bool | |
1005 operator!=(const subtract_with_carry_01& __lhs, | |
1006 const subtract_with_carry_01& __rhs) | |
1007 { return !(__lhs == __rhs); } | |
1008 | |
1009 /** | |
1010 * Inserts the current state of a % subtract_with_carry_01 random number | |
1011 * generator engine @p __x into the output stream @p __os. | |
1012 * | |
1013 * @param __os An output stream. | |
1014 * @param __x A % subtract_with_carry_01 random number generator engine. | |
1015 * | |
1016 * @returns The output stream with the state of @p __x inserted or in | |
1017 * an error state. | |
1018 */ | |
1019 template<typename _RealType1, int __w1, int __s1, int __r1, | |
1020 typename _CharT, typename _Traits> | |
1021 friend std::basic_ostream<_CharT, _Traits>& | |
1022 operator<<(std::basic_ostream<_CharT, _Traits>& __os, | |
1023 const subtract_with_carry_01<_RealType1, __w1, __s1, | |
1024 __r1>& __x); | |
1025 | |
1026 /** | |
1027 * Extracts the current state of a % subtract_with_carry_01 random number | |
1028 * generator engine @p __x from the input stream @p __is. | |
1029 * | |
1030 * @param __is An input stream. | |
1031 * @param __x A % subtract_with_carry_01 random number generator engine. | |
1032 * | |
1033 * @returns The input stream with the state of @p __x extracted or in | |
1034 * an error state. | |
1035 */ | |
1036 template<typename _RealType1, int __w1, int __s1, int __r1, | |
1037 typename _CharT, typename _Traits> | |
1038 friend std::basic_istream<_CharT, _Traits>& | |
1039 operator>>(std::basic_istream<_CharT, _Traits>& __is, | |
1040 subtract_with_carry_01<_RealType1, __w1, __s1, __r1>& __x); | |
1041 | |
1042 private: | |
1043 template<class _Gen> | |
1044 void | |
1045 seed(_Gen& __g, true_type) | |
1046 { return seed(static_cast<unsigned long>(__g)); } | |
1047 | |
1048 template<class _Gen> | |
1049 void | |
1050 seed(_Gen& __g, false_type); | |
1051 | |
1052 void | |
1053 _M_initialize_npows(); | |
1054 | |
1055 static const int __n = (__w + 31) / 32; | |
1056 | |
1057 typedef __detail::_UInt32Type _UInt32Type; | |
1058 _UInt32Type _M_x[long_lag][__n]; | |
1059 _RealType _M_npows[__n]; | |
1060 _UInt32Type _M_carry; | |
1061 int _M_p; | |
1062 }; | |
1063 | |
1064 typedef subtract_with_carry_01<float, 24, 10, 24> ranlux_base_01; | |
1065 | |
1066 // _GLIBCXX_RESOLVE_LIB_DEFECTS | |
1067 // 508. Bad parameters for ranlux64_base_01. | |
1068 typedef subtract_with_carry_01<double, 48, 5, 12> ranlux64_base_01; | |
1069 | |
1070 | |
1071 /** | |
1072 * Produces random numbers from some base engine by discarding blocks of | |
1073 * data. | |
1074 * | |
1075 * 0 <= @p __r <= @p __p | |
1076 */ | |
1077 template<class _UniformRandomNumberGenerator, int __p, int __r> | |
1078 class discard_block | |
1079 { | |
1080 // __glibcxx_class_requires(typename base_type::result_type, | |
1081 // ArithmeticTypeConcept) | |
1082 | |
1083 public: | |
1084 /** The type of the underlying generator engine. */ | |
1085 typedef _UniformRandomNumberGenerator base_type; | |
1086 /** The type of the generated random value. */ | |
1087 typedef typename base_type::result_type result_type; | |
1088 | |
1089 // parameter values | |
1090 static const int block_size = __p; | |
1091 static const int used_block = __r; | |
1092 | |
1093 /** | |
1094 * Constructs a default %discard_block engine. | |
1095 * | |
1096 * The underlying engine is default constructed as well. | |
1097 */ | |
1098 discard_block() | |
1099 : _M_n(0) { } | |
1100 | |
1101 /** | |
1102 * Copy constructs a %discard_block engine. | |
1103 * | |
1104 * Copies an existing base class random number generator. | |
1105 * @param rng An existing (base class) engine object. | |
1106 */ | |
1107 explicit | |
1108 discard_block(const base_type& __rng) | |
1109 : _M_b(__rng), _M_n(0) { } | |
1110 | |
1111 /** | |
1112 * Seed constructs a %discard_block engine. | |
1113 * | |
1114 * Constructs the underlying generator engine seeded with @p __s. | |
1115 * @param __s A seed value for the base class engine. | |
1116 */ | |
1117 explicit | |
1118 discard_block(unsigned long __s) | |
1119 : _M_b(__s), _M_n(0) { } | |
1120 | |
1121 /** | |
1122 * Generator construct a %discard_block engine. | |
1123 * | |
1124 * @param __g A seed generator function. | |
1125 */ | |
1126 template<class _Gen> | |
1127 discard_block(_Gen& __g) | |
1128 : _M_b(__g), _M_n(0) { } | |
1129 | |
1130 /** | |
1131 * Reseeds the %discard_block object with the default seed for the | |
1132 * underlying base class generator engine. | |
1133 */ | |
1134 void seed() | |
1135 { | |
1136 _M_b.seed(); | |
1137 _M_n = 0; | |
1138 } | |
1139 | |
1140 /** | |
1141 * Reseeds the %discard_block object with the given seed generator | |
1142 * function. | |
1143 * @param __g A seed generator function. | |
1144 */ | |
1145 template<class _Gen> | |
1146 void seed(_Gen& __g) | |
1147 { | |
1148 _M_b.seed(__g); | |
1149 _M_n = 0; | |
1150 } | |
1151 | |
1152 /** | |
1153 * Gets a const reference to the underlying generator engine object. | |
1154 */ | |
1155 const base_type& | |
1156 base() const | |
1157 { return _M_b; } | |
1158 | |
1159 /** | |
1160 * Gets the minimum value in the generated random number range. | |
1161 */ | |
1162 result_type | |
1163 min() const | |
1164 { return _M_b.min(); } | |
1165 | |
1166 /** | |
1167 * Gets the maximum value in the generated random number range. | |
1168 */ | |
1169 result_type | |
1170 max() const | |
1171 { return _M_b.max(); } | |
1172 | |
1173 /** | |
1174 * Gets the next value in the generated random number sequence. | |
1175 */ | |
1176 result_type | |
1177 operator()(); | |
1178 | |
1179 /** | |
1180 * Compares two %discard_block random number generator objects of | |
1181 * the same type for equality. | |
1182 * | |
1183 * @param __lhs A %discard_block random number generator object. | |
1184 * @param __rhs Another %discard_block random number generator | |
1185 * object. | |
1186 * | |
1187 * @returns true if the two objects are equal, false otherwise. | |
1188 */ | |
1189 friend bool | |
1190 operator==(const discard_block& __lhs, const discard_block& __rhs) | |
1191 { return (__lhs._M_b == __rhs._M_b) && (__lhs._M_n == __rhs._M_n); } | |
1192 | |
1193 /** | |
1194 * Compares two %discard_block random number generator objects of | |
1195 * the same type for inequality. | |
1196 * | |
1197 * @param __lhs A %discard_block random number generator object. | |
1198 * @param __rhs Another %discard_block random number generator | |
1199 * object. | |
1200 * | |
1201 * @returns true if the two objects are not equal, false otherwise. | |
1202 */ | |
1203 friend bool | |
1204 operator!=(const discard_block& __lhs, const discard_block& __rhs) | |
1205 { return !(__lhs == __rhs); } | |
1206 | |
1207 /** | |
1208 * Inserts the current state of a %discard_block random number | |
1209 * generator engine @p __x into the output stream @p __os. | |
1210 * | |
1211 * @param __os An output stream. | |
1212 * @param __x A %discard_block random number generator engine. | |
1213 * | |
1214 * @returns The output stream with the state of @p __x inserted or in | |
1215 * an error state. | |
1216 */ | |
1217 template<class _UniformRandomNumberGenerator1, int __p1, int __r1, | |
1218 typename _CharT, typename _Traits> | |
1219 friend std::basic_ostream<_CharT, _Traits>& | |
1220 operator<<(std::basic_ostream<_CharT, _Traits>& __os, | |
1221 const discard_block<_UniformRandomNumberGenerator1, | |
1222 __p1, __r1>& __x); | |
1223 | |
1224 /** | |
1225 * Extracts the current state of a % subtract_with_carry random number | |
1226 * generator engine @p __x from the input stream @p __is. | |
1227 * | |
1228 * @param __is An input stream. | |
1229 * @param __x A %discard_block random number generator engine. | |
1230 * | |
1231 * @returns The input stream with the state of @p __x extracted or in | |
1232 * an error state. | |
1233 */ | |
1234 template<class _UniformRandomNumberGenerator1, int __p1, int __r1, | |
1235 typename _CharT, typename _Traits> | |
1236 friend std::basic_istream<_CharT, _Traits>& | |
1237 operator>>(std::basic_istream<_CharT, _Traits>& __is, | |
1238 discard_block<_UniformRandomNumberGenerator1, | |
1239 __p1, __r1>& __x); | |
1240 | |
1241 private: | |
1242 base_type _M_b; | |
1243 int _M_n; | |
1244 }; | |
1245 | |
1246 | |
1247 /** | |
1248 * James's luxury-level-3 integer adaptation of Luescher's generator. | |
1249 */ | |
1250 typedef discard_block< | |
1251 subtract_with_carry<unsigned long, (1UL << 24), 10, 24>, | |
1252 223, | |
1253 24 | |
1254 > ranlux3; | |
1255 | |
1256 /** | |
1257 * James's luxury-level-4 integer adaptation of Luescher's generator. | |
1258 */ | |
1259 typedef discard_block< | |
1260 subtract_with_carry<unsigned long, (1UL << 24), 10, 24>, | |
1261 389, | |
1262 24 | |
1263 > ranlux4; | |
1264 | |
1265 typedef discard_block< | |
1266 subtract_with_carry_01<float, 24, 10, 24>, | |
1267 223, | |
1268 24 | |
1269 > ranlux3_01; | |
1270 | |
1271 typedef discard_block< | |
1272 subtract_with_carry_01<float, 24, 10, 24>, | |
1273 389, | |
1274 24 | |
1275 > ranlux4_01; | |
1276 | |
1277 | |
1278 /** | |
1279 * A random number generator adaptor class that combines two random number | |
1280 * generator engines into a single output sequence. | |
1281 */ | |
1282 template<class _UniformRandomNumberGenerator1, int __s1, | |
1283 class _UniformRandomNumberGenerator2, int __s2> | |
1284 class xor_combine | |
1285 { | |
1286 // __glibcxx_class_requires(typename _UniformRandomNumberGenerator1:: | |
1287 // result_type, ArithmeticTypeConcept) | |
1288 // __glibcxx_class_requires(typename _UniformRandomNumberGenerator2:: | |
1289 // result_type, ArithmeticTypeConcept) | |
1290 | |
1291 public: | |
1292 /** The type of the first underlying generator engine. */ | |
1293 typedef _UniformRandomNumberGenerator1 base1_type; | |
1294 /** The type of the second underlying generator engine. */ | |
1295 typedef _UniformRandomNumberGenerator2 base2_type; | |
1296 | |
1297 private: | |
1298 typedef typename base1_type::result_type _Result_type1; | |
1299 typedef typename base2_type::result_type _Result_type2; | |
1300 | |
1301 public: | |
1302 /** The type of the generated random value. */ | |
1303 typedef typename __gnu_cxx::__conditional_type<(sizeof(_Result_type1) | |
1304 > sizeof(_Result_type2)), | |
1305 _Result_type1, _Result_type2>::__type result_type; | |
1306 | |
1307 // parameter values | |
1308 static const int shift1 = __s1; | |
1309 static const int shift2 = __s2; | |
1310 | |
1311 // constructors and member function | |
1312 xor_combine() | |
1313 : _M_b1(), _M_b2() | |
1314 { _M_initialize_max(); } | |
1315 | |
1316 xor_combine(const base1_type& __rng1, const base2_type& __rng2) | |
1317 : _M_b1(__rng1), _M_b2(__rng2) | |
1318 { _M_initialize_max(); } | |
1319 | |
1320 xor_combine(unsigned long __s) | |
1321 : _M_b1(__s), _M_b2(__s + 1) | |
1322 { _M_initialize_max(); } | |
1323 | |
1324 template<class _Gen> | |
1325 xor_combine(_Gen& __g) | |
1326 : _M_b1(__g), _M_b2(__g) | |
1327 { _M_initialize_max(); } | |
1328 | |
1329 void | |
1330 seed() | |
1331 { | |
1332 _M_b1.seed(); | |
1333 _M_b2.seed(); | |
1334 } | |
1335 | |
1336 template<class _Gen> | |
1337 void | |
1338 seed(_Gen& __g) | |
1339 { | |
1340 _M_b1.seed(__g); | |
1341 _M_b2.seed(__g); | |
1342 } | |
1343 | |
1344 const base1_type& | |
1345 base1() const | |
1346 { return _M_b1; } | |
1347 | |
1348 const base2_type& | |
1349 base2() const | |
1350 { return _M_b2; } | |
1351 | |
1352 result_type | |
1353 min() const | |
1354 { return 0; } | |
1355 | |
1356 result_type | |
1357 max() const | |
1358 { return _M_max; } | |
1359 | |
1360 /** | |
1361 * Gets the next random number in the sequence. | |
1362 */ | |
1363 // NB: Not exactly the TR1 formula, per N2079 instead. | |
1364 result_type | |
1365 operator()() | |
1366 { | |
1367 return ((result_type(_M_b1() - _M_b1.min()) << shift1) | |
1368 ^ (result_type(_M_b2() - _M_b2.min()) << shift2)); | |
1369 } | |
1370 | |
1371 /** | |
1372 * Compares two %xor_combine random number generator objects of | |
1373 * the same type for equality. | |
1374 * | |
1375 * @param __lhs A %xor_combine random number generator object. | |
1376 * @param __rhs Another %xor_combine random number generator | |
1377 * object. | |
1378 * | |
1379 * @returns true if the two objects are equal, false otherwise. | |
1380 */ | |
1381 friend bool | |
1382 operator==(const xor_combine& __lhs, const xor_combine& __rhs) | |
1383 { | |
1384 return (__lhs.base1() == __rhs.base1()) | |
1385 && (__lhs.base2() == __rhs.base2()); | |
1386 } | |
1387 | |
1388 /** | |
1389 * Compares two %xor_combine random number generator objects of | |
1390 * the same type for inequality. | |
1391 * | |
1392 * @param __lhs A %xor_combine random number generator object. | |
1393 * @param __rhs Another %xor_combine random number generator | |
1394 * object. | |
1395 * | |
1396 * @returns true if the two objects are not equal, false otherwise. | |
1397 */ | |
1398 friend bool | |
1399 operator!=(const xor_combine& __lhs, const xor_combine& __rhs) | |
1400 { return !(__lhs == __rhs); } | |
1401 | |
1402 /** | |
1403 * Inserts the current state of a %xor_combine random number | |
1404 * generator engine @p __x into the output stream @p __os. | |
1405 * | |
1406 * @param __os An output stream. | |
1407 * @param __x A %xor_combine random number generator engine. | |
1408 * | |
1409 * @returns The output stream with the state of @p __x inserted or in | |
1410 * an error state. | |
1411 */ | |
1412 template<class _UniformRandomNumberGenerator11, int __s11, | |
1413 class _UniformRandomNumberGenerator21, int __s21, | |
1414 typename _CharT, typename _Traits> | |
1415 friend std::basic_ostream<_CharT, _Traits>& | |
1416 operator<<(std::basic_ostream<_CharT, _Traits>& __os, | |
1417 const xor_combine<_UniformRandomNumberGenerator11, __s11, | |
1418 _UniformRandomNumberGenerator21, __s21>& __x); | |
1419 | |
1420 /** | |
1421 * Extracts the current state of a %xor_combine random number | |
1422 * generator engine @p __x from the input stream @p __is. | |
1423 * | |
1424 * @param __is An input stream. | |
1425 * @param __x A %xor_combine random number generator engine. | |
1426 * | |
1427 * @returns The input stream with the state of @p __x extracted or in | |
1428 * an error state. | |
1429 */ | |
1430 template<class _UniformRandomNumberGenerator11, int __s11, | |
1431 class _UniformRandomNumberGenerator21, int __s21, | |
1432 typename _CharT, typename _Traits> | |
1433 friend std::basic_istream<_CharT, _Traits>& | |
1434 operator>>(std::basic_istream<_CharT, _Traits>& __is, | |
1435 xor_combine<_UniformRandomNumberGenerator11, __s11, | |
1436 _UniformRandomNumberGenerator21, __s21>& __x); | |
1437 | |
1438 private: | |
1439 void | |
1440 _M_initialize_max(); | |
1441 | |
1442 result_type | |
1443 _M_initialize_max_aux(result_type, result_type, int); | |
1444 | |
1445 base1_type _M_b1; | |
1446 base2_type _M_b2; | |
1447 result_type _M_max; | |
1448 }; | |
1449 | |
1450 | |
1451 /** | |
1452 * A standard interface to a platform-specific non-deterministic | |
1453 * random number generator (if any are available). | |
1454 */ | |
1455 class random_device | |
1456 { | |
1457 public: | |
1458 // types | |
1459 typedef unsigned int result_type; | |
1460 | |
1461 // constructors, destructors and member functions | |
1462 | |
1463 #ifdef _GLIBCXX_USE_RANDOM_TR1 | |
1464 | |
1465 explicit | |
1466 random_device(const std::string& __token = "/dev/urandom") | |
1467 { | |
1468 if ((__token != "/dev/urandom" && __token != "/dev/random") | |
1469 || !(_M_file = std::fopen(__token.c_str(), "rb"))) | |
1470 std::__throw_runtime_error(__N("random_device::" | |
1471 "random_device(const std::string&)")); | |
1472 } | |
1473 | |
1474 ~random_device() | |
1475 { std::fclose(_M_file); } | |
1476 | |
1477 #else | |
1478 | |
1479 explicit | |
1480 random_device(const std::string& __token = "mt19937") | |
1481 : _M_mt(_M_strtoul(__token)) { } | |
1482 | |
1483 private: | |
1484 static unsigned long | |
1485 _M_strtoul(const std::string& __str) | |
1486 { | |
1487 unsigned long __ret = 5489UL; | |
1488 if (__str != "mt19937") | |
1489 { | |
1490 const char* __nptr = __str.c_str(); | |
1491 char* __endptr; | |
1492 __ret = std::strtoul(__nptr, &__endptr, 0); | |
1493 if (*__nptr == '\0' || *__endptr != '\0') | |
1494 std::__throw_runtime_error(__N("random_device::_M_strtoul" | |
1495 "(const std::string&)")); | |
1496 } | |
1497 return __ret; | |
1498 } | |
1499 | |
1500 public: | |
1501 | |
1502 #endif | |
1503 | |
1504 result_type | |
1505 min() const | |
1506 { return std::numeric_limits<result_type>::min(); } | |
1507 | |
1508 result_type | |
1509 max() const | |
1510 { return std::numeric_limits<result_type>::max(); } | |
1511 | |
1512 double | |
1513 entropy() const | |
1514 { return 0.0; } | |
1515 | |
1516 result_type | |
1517 operator()() | |
1518 { | |
1519 #ifdef _GLIBCXX_USE_RANDOM_TR1 | |
1520 result_type __ret; | |
1521 std::fread(reinterpret_cast<void*>(&__ret), sizeof(result_type), | |
1522 1, _M_file); | |
1523 return __ret; | |
1524 #else | |
1525 return _M_mt(); | |
1526 #endif | |
1527 } | |
1528 | |
1529 private: | |
1530 random_device(const random_device&); | |
1531 void operator=(const random_device&); | |
1532 | |
1533 #ifdef _GLIBCXX_USE_RANDOM_TR1 | |
1534 FILE* _M_file; | |
1535 #else | |
1536 mt19937 _M_mt; | |
1537 #endif | |
1538 }; | |
1539 | |
1540 /* @} */ // group tr1_random_generators | |
1541 | |
1542 /** | |
1543 * @defgroup tr1_random_distributions Random Number Distributions | |
1544 * @ingroup tr1_random | |
1545 * @{ | |
1546 */ | |
1547 | |
1548 /** | |
1549 * @defgroup tr1_random_distributions_discrete Discrete Distributions | |
1550 * @ingroup tr1_random_distributions | |
1551 * @{ | |
1552 */ | |
1553 | |
1554 /** | |
1555 * @brief Uniform discrete distribution for random numbers. | |
1556 * A discrete random distribution on the range @f$[min, max]@f$ with equal | |
1557 * probability throughout the range. | |
1558 */ | |
1559 template<typename _IntType = int> | |
1560 class uniform_int | |
1561 { | |
1562 __glibcxx_class_requires(_IntType, _IntegerConcept) | |
1563 | |
1564 public: | |
1565 /** The type of the parameters of the distribution. */ | |
1566 typedef _IntType input_type; | |
1567 /** The type of the range of the distribution. */ | |
1568 typedef _IntType result_type; | |
1569 | |
1570 public: | |
1571 /** | |
1572 * Constructs a uniform distribution object. | |
1573 */ | |
1574 explicit | |
1575 uniform_int(_IntType __min = 0, _IntType __max = 9) | |
1576 : _M_min(__min), _M_max(__max) | |
1577 { | |
1578 _GLIBCXX_DEBUG_ASSERT(_M_min <= _M_max); | |
1579 } | |
1580 | |
1581 /** | |
1582 * Gets the inclusive lower bound of the distribution range. | |
1583 */ | |
1584 result_type | |
1585 min() const | |
1586 { return _M_min; } | |
1587 | |
1588 /** | |
1589 * Gets the inclusive upper bound of the distribution range. | |
1590 */ | |
1591 result_type | |
1592 max() const | |
1593 { return _M_max; } | |
1594 | |
1595 /** | |
1596 * Resets the distribution state. | |
1597 * | |
1598 * Does nothing for the uniform integer distribution. | |
1599 */ | |
1600 void | |
1601 reset() { } | |
1602 | |
1603 /** | |
1604 * Gets a uniformly distributed random number in the range | |
1605 * @f$(min, max)@f$. | |
1606 */ | |
1607 template<typename _UniformRandomNumberGenerator> | |
1608 result_type | |
1609 operator()(_UniformRandomNumberGenerator& __urng) | |
1610 { | |
1611 typedef typename _UniformRandomNumberGenerator::result_type | |
1612 _UResult_type; | |
1613 return _M_call(__urng, _M_min, _M_max, | |
1614 typename is_integral<_UResult_type>::type()); | |
1615 } | |
1616 | |
1617 /** | |
1618 * Gets a uniform random number in the range @f$[0, n)@f$. | |
1619 * | |
1620 * This function is aimed at use with std::random_shuffle. | |
1621 */ | |
1622 template<typename _UniformRandomNumberGenerator> | |
1623 result_type | |
1624 operator()(_UniformRandomNumberGenerator& __urng, result_type __n) | |
1625 { | |
1626 typedef typename _UniformRandomNumberGenerator::result_type | |
1627 _UResult_type; | |
1628 return _M_call(__urng, 0, __n - 1, | |
1629 typename is_integral<_UResult_type>::type()); | |
1630 } | |
1631 | |
1632 /** | |
1633 * Inserts a %uniform_int random number distribution @p __x into the | |
1634 * output stream @p os. | |
1635 * | |
1636 * @param __os An output stream. | |
1637 * @param __x A %uniform_int random number distribution. | |
1638 * | |
1639 * @returns The output stream with the state of @p __x inserted or in | |
1640 * an error state. | |
1641 */ | |
1642 template<typename _IntType1, typename _CharT, typename _Traits> | |
1643 friend std::basic_ostream<_CharT, _Traits>& | |
1644 operator<<(std::basic_ostream<_CharT, _Traits>& __os, | |
1645 const uniform_int<_IntType1>& __x); | |
1646 | |
1647 /** | |
1648 * Extracts a %uniform_int random number distribution | |
1649 * @p __x from the input stream @p __is. | |
1650 * | |
1651 * @param __is An input stream. | |
1652 * @param __x A %uniform_int random number generator engine. | |
1653 * | |
1654 * @returns The input stream with @p __x extracted or in an error state. | |
1655 */ | |
1656 template<typename _IntType1, typename _CharT, typename _Traits> | |
1657 friend std::basic_istream<_CharT, _Traits>& | |
1658 operator>>(std::basic_istream<_CharT, _Traits>& __is, | |
1659 uniform_int<_IntType1>& __x); | |
1660 | |
1661 private: | |
1662 template<typename _UniformRandomNumberGenerator> | |
1663 result_type | |
1664 _M_call(_UniformRandomNumberGenerator& __urng, | |
1665 result_type __min, result_type __max, true_type); | |
1666 | |
1667 template<typename _UniformRandomNumberGenerator> | |
1668 result_type | |
1669 _M_call(_UniformRandomNumberGenerator& __urng, | |
1670 result_type __min, result_type __max, false_type) | |
1671 { | |
1672 return result_type((__urng() - __urng.min()) | |
1673 / (__urng.max() - __urng.min()) | |
1674 * (__max - __min + 1)) + __min; | |
1675 } | |
1676 | |
1677 _IntType _M_min; | |
1678 _IntType _M_max; | |
1679 }; | |
1680 | |
1681 | |
1682 /** | |
1683 * @brief A Bernoulli random number distribution. | |
1684 * | |
1685 * Generates a sequence of true and false values with likelihood @f$ p @f$ | |
1686 * that true will come up and @f$ (1 - p) @f$ that false will appear. | |
1687 */ | |
1688 class bernoulli_distribution | |
1689 { | |
1690 public: | |
1691 typedef int input_type; | |
1692 typedef bool result_type; | |
1693 | |
1694 public: | |
1695 /** | |
1696 * Constructs a Bernoulli distribution with likelihood @p p. | |
1697 * | |
1698 * @param __p [IN] The likelihood of a true result being returned. Must | |
1699 * be in the interval @f$ [0, 1] @f$. | |
1700 */ | |
1701 explicit | |
1702 bernoulli_distribution(double __p = 0.5) | |
1703 : _M_p(__p) | |
1704 { | |
1705 _GLIBCXX_DEBUG_ASSERT((_M_p >= 0.0) && (_M_p <= 1.0)); | |
1706 } | |
1707 | |
1708 /** | |
1709 * Gets the @p p parameter of the distribution. | |
1710 */ | |
1711 double | |
1712 p() const | |
1713 { return _M_p; } | |
1714 | |
1715 /** | |
1716 * Resets the distribution state. | |
1717 * | |
1718 * Does nothing for a Bernoulli distribution. | |
1719 */ | |
1720 void | |
1721 reset() { } | |
1722 | |
1723 /** | |
1724 * Gets the next value in the Bernoullian sequence. | |
1725 */ | |
1726 template<class _UniformRandomNumberGenerator> | |
1727 result_type | |
1728 operator()(_UniformRandomNumberGenerator& __urng) | |
1729 { | |
1730 if ((__urng() - __urng.min()) < _M_p * (__urng.max() - __urng.min())) | |
1731 return true; | |
1732 return false; | |
1733 } | |
1734 | |
1735 /** | |
1736 * Inserts a %bernoulli_distribution random number distribution | |
1737 * @p __x into the output stream @p __os. | |
1738 * | |
1739 * @param __os An output stream. | |
1740 * @param __x A %bernoulli_distribution random number distribution. | |
1741 * | |
1742 * @returns The output stream with the state of @p __x inserted or in | |
1743 * an error state. | |
1744 */ | |
1745 template<typename _CharT, typename _Traits> | |
1746 friend std::basic_ostream<_CharT, _Traits>& | |
1747 operator<<(std::basic_ostream<_CharT, _Traits>& __os, | |
1748 const bernoulli_distribution& __x); | |
1749 | |
1750 /** | |
1751 * Extracts a %bernoulli_distribution random number distribution | |
1752 * @p __x from the input stream @p __is. | |
1753 * | |
1754 * @param __is An input stream. | |
1755 * @param __x A %bernoulli_distribution random number generator engine. | |
1756 * | |
1757 * @returns The input stream with @p __x extracted or in an error state. | |
1758 */ | |
1759 template<typename _CharT, typename _Traits> | |
1760 friend std::basic_istream<_CharT, _Traits>& | |
1761 operator>>(std::basic_istream<_CharT, _Traits>& __is, | |
1762 bernoulli_distribution& __x) | |
1763 { return __is >> __x._M_p; } | |
1764 | |
1765 private: | |
1766 double _M_p; | |
1767 }; | |
1768 | |
1769 | |
1770 /** | |
1771 * @brief A discrete geometric random number distribution. | |
1772 * | |
1773 * The formula for the geometric probability mass function is | |
1774 * @f$ p(i) = (1 - p)p^{i-1} @f$ where @f$ p @f$ is the parameter of the | |
1775 * distribution. | |
1776 */ | |
1777 template<typename _IntType = int, typename _RealType = double> | |
1778 class geometric_distribution | |
1779 { | |
1780 public: | |
1781 // types | |
1782 typedef _RealType input_type; | |
1783 typedef _IntType result_type; | |
1784 | |
1785 // constructors and member function | |
1786 explicit | |
1787 geometric_distribution(const _RealType& __p = _RealType(0.5)) | |
1788 : _M_p(__p) | |
1789 { | |
1790 _GLIBCXX_DEBUG_ASSERT((_M_p > 0.0) && (_M_p < 1.0)); | |
1791 _M_initialize(); | |
1792 } | |
1793 | |
1794 /** | |
1795 * Gets the distribution parameter @p p. | |
1796 */ | |
1797 _RealType | |
1798 p() const | |
1799 { return _M_p; } | |
1800 | |
1801 void | |
1802 reset() { } | |
1803 | |
1804 template<class _UniformRandomNumberGenerator> | |
1805 result_type | |
1806 operator()(_UniformRandomNumberGenerator& __urng); | |
1807 | |
1808 /** | |
1809 * Inserts a %geometric_distribution random number distribution | |
1810 * @p __x into the output stream @p __os. | |
1811 * | |
1812 * @param __os An output stream. | |
1813 * @param __x A %geometric_distribution random number distribution. | |
1814 * | |
1815 * @returns The output stream with the state of @p __x inserted or in | |
1816 * an error state. | |
1817 */ | |
1818 template<typename _IntType1, typename _RealType1, | |
1819 typename _CharT, typename _Traits> | |
1820 friend std::basic_ostream<_CharT, _Traits>& | |
1821 operator<<(std::basic_ostream<_CharT, _Traits>& __os, | |
1822 const geometric_distribution<_IntType1, _RealType1>& __x); | |
1823 | |
1824 /** | |
1825 * Extracts a %geometric_distribution random number distribution | |
1826 * @p __x from the input stream @p __is. | |
1827 * | |
1828 * @param __is An input stream. | |
1829 * @param __x A %geometric_distribution random number generator engine. | |
1830 * | |
1831 * @returns The input stream with @p __x extracted or in an error state. | |
1832 */ | |
1833 template<typename _CharT, typename _Traits> | |
1834 friend std::basic_istream<_CharT, _Traits>& | |
1835 operator>>(std::basic_istream<_CharT, _Traits>& __is, | |
1836 geometric_distribution& __x) | |
1837 { | |
1838 __is >> __x._M_p; | |
1839 __x._M_initialize(); | |
1840 return __is; | |
1841 } | |
1842 | |
1843 private: | |
1844 void | |
1845 _M_initialize() | |
1846 { _M_log_p = std::log(_M_p); } | |
1847 | |
1848 _RealType _M_p; | |
1849 _RealType _M_log_p; | |
1850 }; | |
1851 | |
1852 | |
1853 template<typename _RealType> | |
1854 class normal_distribution; | |
1855 | |
1856 /** | |
1857 * @brief A discrete Poisson random number distribution. | |
1858 * | |
1859 * The formula for the Poisson probability mass function is | |
1860 * @f$ p(i) = \frac{mean^i}{i!} e^{-mean} @f$ where @f$ mean @f$ is the | |
1861 * parameter of the distribution. | |
1862 */ | |
1863 template<typename _IntType = int, typename _RealType = double> | |
1864 class poisson_distribution | |
1865 { | |
1866 public: | |
1867 // types | |
1868 typedef _RealType input_type; | |
1869 typedef _IntType result_type; | |
1870 | |
1871 // constructors and member function | |
1872 explicit | |
1873 poisson_distribution(const _RealType& __mean = _RealType(1)) | |
1874 : _M_mean(__mean), _M_nd() | |
1875 { | |
1876 _GLIBCXX_DEBUG_ASSERT(_M_mean > 0.0); | |
1877 _M_initialize(); | |
1878 } | |
1879 | |
1880 /** | |
1881 * Gets the distribution parameter @p mean. | |
1882 */ | |
1883 _RealType | |
1884 mean() const | |
1885 { return _M_mean; } | |
1886 | |
1887 void | |
1888 reset() | |
1889 { _M_nd.reset(); } | |
1890 | |
1891 template<class _UniformRandomNumberGenerator> | |
1892 result_type | |
1893 operator()(_UniformRandomNumberGenerator& __urng); | |
1894 | |
1895 /** | |
1896 * Inserts a %poisson_distribution random number distribution | |
1897 * @p __x into the output stream @p __os. | |
1898 * | |
1899 * @param __os An output stream. | |
1900 * @param __x A %poisson_distribution random number distribution. | |
1901 * | |
1902 * @returns The output stream with the state of @p __x inserted or in | |
1903 * an error state. | |
1904 */ | |
1905 template<typename _IntType1, typename _RealType1, | |
1906 typename _CharT, typename _Traits> | |
1907 friend std::basic_ostream<_CharT, _Traits>& | |
1908 operator<<(std::basic_ostream<_CharT, _Traits>& __os, | |
1909 const poisson_distribution<_IntType1, _RealType1>& __x); | |
1910 | |
1911 /** | |
1912 * Extracts a %poisson_distribution random number distribution | |
1913 * @p __x from the input stream @p __is. | |
1914 * | |
1915 * @param __is An input stream. | |
1916 * @param __x A %poisson_distribution random number generator engine. | |
1917 * | |
1918 * @returns The input stream with @p __x extracted or in an error state. | |
1919 */ | |
1920 template<typename _IntType1, typename _RealType1, | |
1921 typename _CharT, typename _Traits> | |
1922 friend std::basic_istream<_CharT, _Traits>& | |
1923 operator>>(std::basic_istream<_CharT, _Traits>& __is, | |
1924 poisson_distribution<_IntType1, _RealType1>& __x); | |
1925 | |
1926 private: | |
1927 void | |
1928 _M_initialize(); | |
1929 | |
1930 // NB: Unused when _GLIBCXX_USE_C99_MATH_TR1 is undefined. | |
1931 normal_distribution<_RealType> _M_nd; | |
1932 | |
1933 _RealType _M_mean; | |
1934 | |
1935 // Hosts either log(mean) or the threshold of the simple method. | |
1936 _RealType _M_lm_thr; | |
1937 #if _GLIBCXX_USE_C99_MATH_TR1 | |
1938 _RealType _M_lfm, _M_sm, _M_d, _M_scx, _M_1cx, _M_c2b, _M_cb; | |
1939 #endif | |
1940 }; | |
1941 | |
1942 | |
1943 /** | |
1944 * @brief A discrete binomial random number distribution. | |
1945 * | |
1946 * The formula for the binomial probability mass function is | |
1947 * @f$ p(i) = \binom{n}{i} p^i (1 - p)^{t - i} @f$ where @f$ t @f$ | |
1948 * and @f$ p @f$ are the parameters of the distribution. | |
1949 */ | |
1950 template<typename _IntType = int, typename _RealType = double> | |
1951 class binomial_distribution | |
1952 { | |
1953 public: | |
1954 // types | |
1955 typedef _RealType input_type; | |
1956 typedef _IntType result_type; | |
1957 | |
1958 // constructors and member function | |
1959 explicit | |
1960 binomial_distribution(_IntType __t = 1, | |
1961 const _RealType& __p = _RealType(0.5)) | |
1962 : _M_t(__t), _M_p(__p), _M_nd() | |
1963 { | |
1964 _GLIBCXX_DEBUG_ASSERT((_M_t >= 0) && (_M_p >= 0.0) && (_M_p <= 1.0)); | |
1965 _M_initialize(); | |
1966 } | |
1967 | |
1968 /** | |
1969 * Gets the distribution @p t parameter. | |
1970 */ | |
1971 _IntType | |
1972 t() const | |
1973 { return _M_t; } | |
1974 | |
1975 /** | |
1976 * Gets the distribution @p p parameter. | |
1977 */ | |
1978 _RealType | |
1979 p() const | |
1980 { return _M_p; } | |
1981 | |
1982 void | |
1983 reset() | |
1984 { _M_nd.reset(); } | |
1985 | |
1986 template<class _UniformRandomNumberGenerator> | |
1987 result_type | |
1988 operator()(_UniformRandomNumberGenerator& __urng); | |
1989 | |
1990 /** | |
1991 * Inserts a %binomial_distribution random number distribution | |
1992 * @p __x into the output stream @p __os. | |
1993 * | |
1994 * @param __os An output stream. | |
1995 * @param __x A %binomial_distribution random number distribution. | |
1996 * | |
1997 * @returns The output stream with the state of @p __x inserted or in | |
1998 * an error state. | |
1999 */ | |
2000 template<typename _IntType1, typename _RealType1, | |
2001 typename _CharT, typename _Traits> | |
2002 friend std::basic_ostream<_CharT, _Traits>& | |
2003 operator<<(std::basic_ostream<_CharT, _Traits>& __os, | |
2004 const binomial_distribution<_IntType1, _RealType1>& __x); | |
2005 | |
2006 /** | |
2007 * Extracts a %binomial_distribution random number distribution | |
2008 * @p __x from the input stream @p __is. | |
2009 * | |
2010 * @param __is An input stream. | |
2011 * @param __x A %binomial_distribution random number generator engine. | |
2012 * | |
2013 * @returns The input stream with @p __x extracted or in an error state. | |
2014 */ | |
2015 template<typename _IntType1, typename _RealType1, | |
2016 typename _CharT, typename _Traits> | |
2017 friend std::basic_istream<_CharT, _Traits>& | |
2018 operator>>(std::basic_istream<_CharT, _Traits>& __is, | |
2019 binomial_distribution<_IntType1, _RealType1>& __x); | |
2020 | |
2021 private: | |
2022 void | |
2023 _M_initialize(); | |
2024 | |
2025 template<class _UniformRandomNumberGenerator> | |
2026 result_type | |
2027 _M_waiting(_UniformRandomNumberGenerator& __urng, _IntType __t); | |
2028 | |
2029 // NB: Unused when _GLIBCXX_USE_C99_MATH_TR1 is undefined. | |
2030 normal_distribution<_RealType> _M_nd; | |
2031 | |
2032 _RealType _M_q; | |
2033 #if _GLIBCXX_USE_C99_MATH_TR1 | |
2034 _RealType _M_d1, _M_d2, _M_s1, _M_s2, _M_c, | |
2035 _M_a1, _M_a123, _M_s, _M_lf, _M_lp1p; | |
2036 #endif | |
2037 _RealType _M_p; | |
2038 _IntType _M_t; | |
2039 | |
2040 bool _M_easy; | |
2041 }; | |
2042 | |
2043 /* @} */ // group tr1_random_distributions_discrete | |
2044 | |
2045 /** | |
2046 * @defgroup tr1_random_distributions_continuous Continuous Distributions | |
2047 * @ingroup tr1_random_distributions | |
2048 * @{ | |
2049 */ | |
2050 | |
2051 /** | |
2052 * @brief Uniform continuous distribution for random numbers. | |
2053 * | |
2054 * A continuous random distribution on the range [min, max) with equal | |
2055 * probability throughout the range. The URNG should be real-valued and | |
2056 * deliver number in the range [0, 1). | |
2057 */ | |
2058 template<typename _RealType = double> | |
2059 class uniform_real | |
2060 { | |
2061 public: | |
2062 // types | |
2063 typedef _RealType input_type; | |
2064 typedef _RealType result_type; | |
2065 | |
2066 public: | |
2067 /** | |
2068 * Constructs a uniform_real object. | |
2069 * | |
2070 * @param __min [IN] The lower bound of the distribution. | |
2071 * @param __max [IN] The upper bound of the distribution. | |
2072 */ | |
2073 explicit | |
2074 uniform_real(_RealType __min = _RealType(0), | |
2075 _RealType __max = _RealType(1)) | |
2076 : _M_min(__min), _M_max(__max) | |
2077 { | |
2078 _GLIBCXX_DEBUG_ASSERT(_M_min <= _M_max); | |
2079 } | |
2080 | |
2081 result_type | |
2082 min() const | |
2083 { return _M_min; } | |
2084 | |
2085 result_type | |
2086 max() const | |
2087 { return _M_max; } | |
2088 | |
2089 void | |
2090 reset() { } | |
2091 | |
2092 template<class _UniformRandomNumberGenerator> | |
2093 result_type | |
2094 operator()(_UniformRandomNumberGenerator& __urng) | |
2095 { return (__urng() * (_M_max - _M_min)) + _M_min; } | |
2096 | |
2097 /** | |
2098 * Inserts a %uniform_real random number distribution @p __x into the | |
2099 * output stream @p __os. | |
2100 * | |
2101 * @param __os An output stream. | |
2102 * @param __x A %uniform_real random number distribution. | |
2103 * | |
2104 * @returns The output stream with the state of @p __x inserted or in | |
2105 * an error state. | |
2106 */ | |
2107 template<typename _RealType1, typename _CharT, typename _Traits> | |
2108 friend std::basic_ostream<_CharT, _Traits>& | |
2109 operator<<(std::basic_ostream<_CharT, _Traits>& __os, | |
2110 const uniform_real<_RealType1>& __x); | |
2111 | |
2112 /** | |
2113 * Extracts a %uniform_real random number distribution | |
2114 * @p __x from the input stream @p __is. | |
2115 * | |
2116 * @param __is An input stream. | |
2117 * @param __x A %uniform_real random number generator engine. | |
2118 * | |
2119 * @returns The input stream with @p __x extracted or in an error state. | |
2120 */ | |
2121 template<typename _RealType1, typename _CharT, typename _Traits> | |
2122 friend std::basic_istream<_CharT, _Traits>& | |
2123 operator>>(std::basic_istream<_CharT, _Traits>& __is, | |
2124 uniform_real<_RealType1>& __x); | |
2125 | |
2126 private: | |
2127 _RealType _M_min; | |
2128 _RealType _M_max; | |
2129 }; | |
2130 | |
2131 | |
2132 /** | |
2133 * @brief An exponential continuous distribution for random numbers. | |
2134 * | |
2135 * The formula for the exponential probability mass function is | |
2136 * @f$ p(x) = \lambda e^{-\lambda x} @f$. | |
2137 * | |
2138 * <table border=1 cellpadding=10 cellspacing=0> | |
2139 * <caption align=top>Distribution Statistics</caption> | |
2140 * <tr><td>Mean</td><td>@f$ \frac{1}{\lambda} @f$</td></tr> | |
2141 * <tr><td>Median</td><td>@f$ \frac{\ln 2}{\lambda} @f$</td></tr> | |
2142 * <tr><td>Mode</td><td>@f$ zero @f$</td></tr> | |
2143 * <tr><td>Range</td><td>@f$[0, \infty]@f$</td></tr> | |
2144 * <tr><td>Standard Deviation</td><td>@f$ \frac{1}{\lambda} @f$</td></tr> | |
2145 * </table> | |
2146 */ | |
2147 template<typename _RealType = double> | |
2148 class exponential_distribution | |
2149 { | |
2150 public: | |
2151 // types | |
2152 typedef _RealType input_type; | |
2153 typedef _RealType result_type; | |
2154 | |
2155 public: | |
2156 /** | |
2157 * Constructs an exponential distribution with inverse scale parameter | |
2158 * @f$ \lambda @f$. | |
2159 */ | |
2160 explicit | |
2161 exponential_distribution(const result_type& __lambda = result_type(1)) | |
2162 : _M_lambda(__lambda) | |
2163 { | |
2164 _GLIBCXX_DEBUG_ASSERT(_M_lambda > 0); | |
2165 } | |
2166 | |
2167 /** | |
2168 * Gets the inverse scale parameter of the distribution. | |
2169 */ | |
2170 _RealType | |
2171 lambda() const | |
2172 { return _M_lambda; } | |
2173 | |
2174 /** | |
2175 * Resets the distribution. | |
2176 * | |
2177 * Has no effect on exponential distributions. | |
2178 */ | |
2179 void | |
2180 reset() { } | |
2181 | |
2182 template<class _UniformRandomNumberGenerator> | |
2183 result_type | |
2184 operator()(_UniformRandomNumberGenerator& __urng) | |
2185 { return -std::log(__urng()) / _M_lambda; } | |
2186 | |
2187 /** | |
2188 * Inserts a %exponential_distribution random number distribution | |
2189 * @p __x into the output stream @p __os. | |
2190 * | |
2191 * @param __os An output stream. | |
2192 * @param __x A %exponential_distribution random number distribution. | |
2193 * | |
2194 * @returns The output stream with the state of @p __x inserted or in | |
2195 * an error state. | |
2196 */ | |
2197 template<typename _RealType1, typename _CharT, typename _Traits> | |
2198 friend std::basic_ostream<_CharT, _Traits>& | |
2199 operator<<(std::basic_ostream<_CharT, _Traits>& __os, | |
2200 const exponential_distribution<_RealType1>& __x); | |
2201 | |
2202 /** | |
2203 * Extracts a %exponential_distribution random number distribution | |
2204 * @p __x from the input stream @p __is. | |
2205 * | |
2206 * @param __is An input stream. | |
2207 * @param __x A %exponential_distribution random number | |
2208 * generator engine. | |
2209 * | |
2210 * @returns The input stream with @p __x extracted or in an error state. | |
2211 */ | |
2212 template<typename _CharT, typename _Traits> | |
2213 friend std::basic_istream<_CharT, _Traits>& | |
2214 operator>>(std::basic_istream<_CharT, _Traits>& __is, | |
2215 exponential_distribution& __x) | |
2216 { return __is >> __x._M_lambda; } | |
2217 | |
2218 private: | |
2219 result_type _M_lambda; | |
2220 }; | |
2221 | |
2222 | |
2223 /** | |
2224 * @brief A normal continuous distribution for random numbers. | |
2225 * | |
2226 * The formula for the normal probability mass function is | |
2227 * @f$ p(x) = \frac{1}{\sigma \sqrt{2 \pi}} | |
2228 * e^{- \frac{{x - mean}^ {2}}{2 \sigma ^ {2}} } @f$. | |
2229 */ | |
2230 template<typename _RealType = double> | |
2231 class normal_distribution | |
2232 { | |
2233 public: | |
2234 // types | |
2235 typedef _RealType input_type; | |
2236 typedef _RealType result_type; | |
2237 | |
2238 public: | |
2239 /** | |
2240 * Constructs a normal distribution with parameters @f$ mean @f$ and | |
2241 * @f$ \sigma @f$. | |
2242 */ | |
2243 explicit | |
2244 normal_distribution(const result_type& __mean = result_type(0), | |
2245 const result_type& __sigma = result_type(1)) | |
2246 : _M_mean(__mean), _M_sigma(__sigma), _M_saved_available(false) | |
2247 { | |
2248 _GLIBCXX_DEBUG_ASSERT(_M_sigma > 0); | |
2249 } | |
2250 | |
2251 /** | |
2252 * Gets the mean of the distribution. | |
2253 */ | |
2254 _RealType | |
2255 mean() const | |
2256 { return _M_mean; } | |
2257 | |
2258 /** | |
2259 * Gets the @f$ \sigma @f$ of the distribution. | |
2260 */ | |
2261 _RealType | |
2262 sigma() const | |
2263 { return _M_sigma; } | |
2264 | |
2265 /** | |
2266 * Resets the distribution. | |
2267 */ | |
2268 void | |
2269 reset() | |
2270 { _M_saved_available = false; } | |
2271 | |
2272 template<class _UniformRandomNumberGenerator> | |
2273 result_type | |
2274 operator()(_UniformRandomNumberGenerator& __urng); | |
2275 | |
2276 /** | |
2277 * Inserts a %normal_distribution random number distribution | |
2278 * @p __x into the output stream @p __os. | |
2279 * | |
2280 * @param __os An output stream. | |
2281 * @param __x A %normal_distribution random number distribution. | |
2282 * | |
2283 * @returns The output stream with the state of @p __x inserted or in | |
2284 * an error state. | |
2285 */ | |
2286 template<typename _RealType1, typename _CharT, typename _Traits> | |
2287 friend std::basic_ostream<_CharT, _Traits>& | |
2288 operator<<(std::basic_ostream<_CharT, _Traits>& __os, | |
2289 const normal_distribution<_RealType1>& __x); | |
2290 | |
2291 /** | |
2292 * Extracts a %normal_distribution random number distribution | |
2293 * @p __x from the input stream @p __is. | |
2294 * | |
2295 * @param __is An input stream. | |
2296 * @param __x A %normal_distribution random number generator engine. | |
2297 * | |
2298 * @returns The input stream with @p __x extracted or in an error state. | |
2299 */ | |
2300 template<typename _RealType1, typename _CharT, typename _Traits> | |
2301 friend std::basic_istream<_CharT, _Traits>& | |
2302 operator>>(std::basic_istream<_CharT, _Traits>& __is, | |
2303 normal_distribution<_RealType1>& __x); | |
2304 | |
2305 private: | |
2306 result_type _M_mean; | |
2307 result_type _M_sigma; | |
2308 result_type _M_saved; | |
2309 bool _M_saved_available; | |
2310 }; | |
2311 | |
2312 | |
2313 /** | |
2314 * @brief A gamma continuous distribution for random numbers. | |
2315 * | |
2316 * The formula for the gamma probability mass function is | |
2317 * @f$ p(x) = \frac{1}{\Gamma(\alpha)} x^{\alpha - 1} e^{-x} @f$. | |
2318 */ | |
2319 template<typename _RealType = double> | |
2320 class gamma_distribution | |
2321 { | |
2322 public: | |
2323 // types | |
2324 typedef _RealType input_type; | |
2325 typedef _RealType result_type; | |
2326 | |
2327 public: | |
2328 /** | |
2329 * Constructs a gamma distribution with parameters @f$ \alpha @f$. | |
2330 */ | |
2331 explicit | |
2332 gamma_distribution(const result_type& __alpha_val = result_type(1)) | |
2333 : _M_alpha(__alpha_val) | |
2334 { | |
2335 _GLIBCXX_DEBUG_ASSERT(_M_alpha > 0); | |
2336 _M_initialize(); | |
2337 } | |
2338 | |
2339 /** | |
2340 * Gets the @f$ \alpha @f$ of the distribution. | |
2341 */ | |
2342 _RealType | |
2343 alpha() const | |
2344 { return _M_alpha; } | |
2345 | |
2346 /** | |
2347 * Resets the distribution. | |
2348 */ | |
2349 void | |
2350 reset() { } | |
2351 | |
2352 template<class _UniformRandomNumberGenerator> | |
2353 result_type | |
2354 operator()(_UniformRandomNumberGenerator& __urng); | |
2355 | |
2356 /** | |
2357 * Inserts a %gamma_distribution random number distribution | |
2358 * @p __x into the output stream @p __os. | |
2359 * | |
2360 * @param __os An output stream. | |
2361 * @param __x A %gamma_distribution random number distribution. | |
2362 * | |
2363 * @returns The output stream with the state of @p __x inserted or in | |
2364 * an error state. | |
2365 */ | |
2366 template<typename _RealType1, typename _CharT, typename _Traits> | |
2367 friend std::basic_ostream<_CharT, _Traits>& | |
2368 operator<<(std::basic_ostream<_CharT, _Traits>& __os, | |
2369 const gamma_distribution<_RealType1>& __x); | |
2370 | |
2371 /** | |
2372 * Extracts a %gamma_distribution random number distribution | |
2373 * @p __x from the input stream @p __is. | |
2374 * | |
2375 * @param __is An input stream. | |
2376 * @param __x A %gamma_distribution random number generator engine. | |
2377 * | |
2378 * @returns The input stream with @p __x extracted or in an error state. | |
2379 */ | |
2380 template<typename _CharT, typename _Traits> | |
2381 friend std::basic_istream<_CharT, _Traits>& | |
2382 operator>>(std::basic_istream<_CharT, _Traits>& __is, | |
2383 gamma_distribution& __x) | |
2384 { | |
2385 __is >> __x._M_alpha; | |
2386 __x._M_initialize(); | |
2387 return __is; | |
2388 } | |
2389 | |
2390 private: | |
2391 void | |
2392 _M_initialize(); | |
2393 | |
2394 result_type _M_alpha; | |
2395 | |
2396 // Hosts either lambda of GB or d of modified Vaduva's. | |
2397 result_type _M_l_d; | |
2398 }; | |
2399 | |
2400 /* @} */ // group tr1_random_distributions_continuous | |
2401 /* @} */ // group tr1_random_distributions | |
2402 /* @} */ // group tr1_random | |
2403 | |
2404 _GLIBCXX_END_NAMESPACE_TR1 | |
2405 } | |
2406 | |
2407 #include <tr1_impl/random.tcc> | |
OLD | NEW |