| // random number generation -*- C++ -*- |
| |
| // Copyright (C) 2007, 2008, 2009 Free Software Foundation, Inc. |
| // |
| // This file is part of the GNU ISO C++ Library. This library is free |
| // software; you can redistribute it and/or modify it under the |
| // terms of the GNU General Public License as published by the |
| // Free Software Foundation; either version 3, or (at your option) |
| // any later version. |
| |
| // This library is distributed in the hope that it will be useful, |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| // GNU General Public License for more details. |
| |
| // Under Section 7 of GPL version 3, you are granted additional |
| // permissions described in the GCC Runtime Library Exception, version |
| // 3.1, as published by the Free Software Foundation. |
| |
| // You should have received a copy of the GNU General Public License and |
| // a copy of the GCC Runtime Library Exception along with this program; |
| // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| // <http://www.gnu.org/licenses/>. |
| |
| /** |
| * @file tr1_impl/random |
| * This is an internal header file, included by other library headers. |
| * You should not attempt to use it directly. |
| */ |
| |
| namespace std |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_TR1 |
| |
| // [5.1] Random number generation |
| |
| /** |
| * @defgroup tr1_random Random Number Generation |
| * @ingroup numerics |
| * A facility for generating random numbers on selected distributions. |
| * @{ |
| */ |
| |
| /* |
| * Implementation-space details. |
| */ |
| namespace __detail |
| { |
| template<typename _UIntType, int __w, |
| bool = __w < std::numeric_limits<_UIntType>::digits> |
| struct _Shift |
| { static const _UIntType __value = 0; }; |
| |
| template<typename _UIntType, int __w> |
| struct _Shift<_UIntType, __w, true> |
| { static const _UIntType __value = _UIntType(1) << __w; }; |
| |
| template<typename _Tp, _Tp __a, _Tp __c, _Tp __m, bool> |
| struct _Mod; |
| |
| // Dispatch based on modulus value to prevent divide-by-zero compile-time |
| // errors when m == 0. |
| template<typename _Tp, _Tp __a, _Tp __c, _Tp __m> |
| inline _Tp |
| __mod(_Tp __x) |
| { return _Mod<_Tp, __a, __c, __m, __m == 0>::__calc(__x); } |
| |
| typedef __gnu_cxx::__conditional_type<(sizeof(unsigned) == 4), |
| unsigned, unsigned long>::__type _UInt32Type; |
| |
| /* |
| * An adaptor class for converting the output of any Generator into |
| * the input for a specific Distribution. |
| */ |
| template<typename _Engine, typename _Distribution> |
| struct _Adaptor |
| { |
| typedef typename remove_reference<_Engine>::type _BEngine; |
| typedef typename _BEngine::result_type _Engine_result_type; |
| typedef typename _Distribution::input_type result_type; |
| |
| public: |
| _Adaptor(const _Engine& __g) |
| : _M_g(__g) { } |
| |
| result_type |
| min() const |
| { |
| result_type __return_value; |
| if (is_integral<_Engine_result_type>::value |
| && is_integral<result_type>::value) |
| __return_value = _M_g.min(); |
| else |
| __return_value = result_type(0); |
| return __return_value; |
| } |
| |
| result_type |
| max() const |
| { |
| result_type __return_value; |
| if (is_integral<_Engine_result_type>::value |
| && is_integral<result_type>::value) |
| __return_value = _M_g.max(); |
| else if (!is_integral<result_type>::value) |
| __return_value = result_type(1); |
| else |
| __return_value = std::numeric_limits<result_type>::max() - 1; |
| return __return_value; |
| } |
| |
| /* |
| * Converts a value generated by the adapted random number generator |
| * into a value in the input domain for the dependent random number |
| * distribution. |
| * |
| * Because the type traits are compile time constants only the |
| * appropriate clause of the if statements will actually be emitted |
| * by the compiler. |
| */ |
| result_type |
| operator()() |
| { |
| result_type __return_value; |
| if (is_integral<_Engine_result_type>::value |
| && is_integral<result_type>::value) |
| __return_value = _M_g(); |
| else if (!is_integral<_Engine_result_type>::value |
| && !is_integral<result_type>::value) |
| __return_value = result_type(_M_g() - _M_g.min()) |
| / result_type(_M_g.max() - _M_g.min()); |
| else if (is_integral<_Engine_result_type>::value |
| && !is_integral<result_type>::value) |
| __return_value = result_type(_M_g() - _M_g.min()) |
| / result_type(_M_g.max() - _M_g.min() + result_type(1)); |
| else |
| __return_value = (((_M_g() - _M_g.min()) |
| / (_M_g.max() - _M_g.min())) |
| * std::numeric_limits<result_type>::max()); |
| return __return_value; |
| } |
| |
| private: |
| _Engine _M_g; |
| }; |
| |
| // Specialization for _Engine*. |
| template<typename _Engine, typename _Distribution> |
| struct _Adaptor<_Engine*, _Distribution> |
| { |
| typedef typename _Engine::result_type _Engine_result_type; |
| typedef typename _Distribution::input_type result_type; |
| |
| public: |
| _Adaptor(_Engine* __g) |
| : _M_g(__g) { } |
| |
| result_type |
| min() const |
| { |
| result_type __return_value; |
| if (is_integral<_Engine_result_type>::value |
| && is_integral<result_type>::value) |
| __return_value = _M_g->min(); |
| else |
| __return_value = result_type(0); |
| return __return_value; |
| } |
| |
| result_type |
| max() const |
| { |
| result_type __return_value; |
| if (is_integral<_Engine_result_type>::value |
| && is_integral<result_type>::value) |
| __return_value = _M_g->max(); |
| else if (!is_integral<result_type>::value) |
| __return_value = result_type(1); |
| else |
| __return_value = std::numeric_limits<result_type>::max() - 1; |
| return __return_value; |
| } |
| |
| result_type |
| operator()() |
| { |
| result_type __return_value; |
| if (is_integral<_Engine_result_type>::value |
| && is_integral<result_type>::value) |
| __return_value = (*_M_g)(); |
| else if (!is_integral<_Engine_result_type>::value |
| && !is_integral<result_type>::value) |
| __return_value = result_type((*_M_g)() - _M_g->min()) |
| / result_type(_M_g->max() - _M_g->min()); |
| else if (is_integral<_Engine_result_type>::value |
| && !is_integral<result_type>::value) |
| __return_value = result_type((*_M_g)() - _M_g->min()) |
| / result_type(_M_g->max() - _M_g->min() + result_type(1)); |
| else |
| __return_value = ((((*_M_g)() - _M_g->min()) |
| / (_M_g->max() - _M_g->min())) |
| * std::numeric_limits<result_type>::max()); |
| return __return_value; |
| } |
| |
| private: |
| _Engine* _M_g; |
| }; |
| } // namespace __detail |
| |
| /** |
| * Produces random numbers on a given distribution function using a |
| * non-uniform random number generation engine. |
| * |
| * @todo the engine_value_type needs to be studied more carefully. |
| */ |
| template<typename _Engine, typename _Dist> |
| class variate_generator |
| { |
| // Concept requirements. |
| __glibcxx_class_requires(_Engine, _CopyConstructibleConcept) |
| // __glibcxx_class_requires(_Engine, _EngineConcept) |
| // __glibcxx_class_requires(_Dist, _EngineConcept) |
| |
| public: |
| typedef _Engine engine_type; |
| typedef __detail::_Adaptor<_Engine, _Dist> engine_value_type; |
| typedef _Dist distribution_type; |
| typedef typename _Dist::result_type result_type; |
| |
| // tr1:5.1.1 table 5.1 requirement |
| typedef typename __gnu_cxx::__enable_if< |
| is_arithmetic<result_type>::value, result_type>::__type _IsValidType; |
| |
| /** |
| * Constructs a variate generator with the uniform random number |
| * generator @p __eng for the random distribution @p __dist. |
| * |
| * @throws Any exceptions which may thrown by the copy constructors of |
| * the @p _Engine or @p _Dist objects. |
| */ |
| variate_generator(engine_type __eng, distribution_type __dist) |
| : _M_engine(__eng), _M_dist(__dist) { } |
| |
| /** |
| * Gets the next generated value on the distribution. |
| */ |
| result_type |
| operator()() |
| { return _M_dist(_M_engine); } |
| |
| /** |
| * WTF? |
| */ |
| template<typename _Tp> |
| result_type |
| operator()(_Tp __value) |
| { return _M_dist(_M_engine, __value); } |
| |
| /** |
| * Gets a reference to the underlying uniform random number generator |
| * object. |
| */ |
| engine_value_type& |
| engine() |
| { return _M_engine; } |
| |
| /** |
| * Gets a const reference to the underlying uniform random number |
| * generator object. |
| */ |
| const engine_value_type& |
| engine() const |
| { return _M_engine; } |
| |
| /** |
| * Gets a reference to the underlying random distribution. |
| */ |
| distribution_type& |
| distribution() |
| { return _M_dist; } |
| |
| /** |
| * Gets a const reference to the underlying random distribution. |
| */ |
| const distribution_type& |
| distribution() const |
| { return _M_dist; } |
| |
| /** |
| * Gets the closed lower bound of the distribution interval. |
| */ |
| result_type |
| min() const |
| { return this->distribution().min(); } |
| |
| /** |
| * Gets the closed upper bound of the distribution interval. |
| */ |
| result_type |
| max() const |
| { return this->distribution().max(); } |
| |
| private: |
| engine_value_type _M_engine; |
| distribution_type _M_dist; |
| }; |
| |
| |
| /** |
| * @defgroup tr1_random_generators Random Number Generators |
| * @ingroup tr1_random |
| * |
| * These classes define objects which provide random or pseudorandom |
| * numbers, either from a discrete or a continuous interval. The |
| * random number generator supplied as a part of this library are |
| * all uniform random number generators which provide a sequence of |
| * random number uniformly distributed over their range. |
| * |
| * A number generator is a function object with an operator() that |
| * takes zero arguments and returns a number. |
| * |
| * A compliant random number generator must satisfy the following |
| * requirements. <table border=1 cellpadding=10 cellspacing=0> |
| * <caption align=top>Random Number Generator Requirements</caption> |
| * <tr><td>To be documented.</td></tr> </table> |
| * |
| * @{ |
| */ |
| |
| /** |
| * @brief A model of a linear congruential random number generator. |
| * |
| * A random number generator that produces pseudorandom numbers using the |
| * linear function @f$x_{i+1}\leftarrow(ax_{i} + c) \bmod m @f$. |
| * |
| * The template parameter @p _UIntType must be an unsigned integral type |
| * large enough to store values up to (__m-1). If the template parameter |
| * @p __m is 0, the modulus @p __m used is |
| * std::numeric_limits<_UIntType>::max() plus 1. Otherwise, the template |
| * parameters @p __a and @p __c must be less than @p __m. |
| * |
| * The size of the state is @f$ 1 @f$. |
| */ |
| template<class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m> |
| class linear_congruential |
| { |
| __glibcxx_class_requires(_UIntType, _UnsignedIntegerConcept) |
| // __glibcpp_class_requires(__a < __m && __c < __m) |
| |
| public: |
| /** The type of the generated random value. */ |
| typedef _UIntType result_type; |
| |
| /** The multiplier. */ |
| static const _UIntType multiplier = __a; |
| /** An increment. */ |
| static const _UIntType increment = __c; |
| /** The modulus. */ |
| static const _UIntType modulus = __m; |
| |
| /** |
| * Constructs a %linear_congruential random number generator engine with |
| * seed @p __s. The default seed value is 1. |
| * |
| * @param __s The initial seed value. |
| */ |
| explicit |
| linear_congruential(unsigned long __x0 = 1) |
| { this->seed(__x0); } |
| |
| /** |
| * Constructs a %linear_congruential random number generator engine |
| * seeded from the generator function @p __g. |
| * |
| * @param __g The seed generator function. |
| */ |
| template<class _Gen> |
| linear_congruential(_Gen& __g) |
| { this->seed(__g); } |
| |
| /** |
| * Reseeds the %linear_congruential random number generator engine |
| * sequence to the seed @g __s. |
| * |
| * @param __s The new seed. |
| */ |
| void |
| seed(unsigned long __s = 1); |
| |
| /** |
| * Reseeds the %linear_congruential random number generator engine |
| * sequence using values from the generator function @p __g. |
| * |
| * @param __g the seed generator function. |
| */ |
| template<class _Gen> |
| void |
| seed(_Gen& __g) |
| { seed(__g, typename is_fundamental<_Gen>::type()); } |
| |
| /** |
| * Gets the smallest possible value in the output range. |
| * |
| * The minimum depends on the @p __c parameter: if it is zero, the |
| * minimum generated must be > 0, otherwise 0 is allowed. |
| */ |
| result_type |
| min() const |
| { return (__detail::__mod<_UIntType, 1, 0, __m>(__c) == 0) ? 1 : 0; } |
| |
| /** |
| * Gets the largest possible value in the output range. |
| */ |
| result_type |
| max() const |
| { return __m - 1; } |
| |
| /** |
| * Gets the next random number in the sequence. |
| */ |
| result_type |
| operator()(); |
| |
| /** |
| * Compares two linear congruential random number generator |
| * objects of the same type for equality. |
| * |
| * @param __lhs A linear congruential random number generator object. |
| * @param __rhs Another linear congruential random number generator obj. |
| * |
| * @returns true if the two objects are equal, false otherwise. |
| */ |
| friend bool |
| operator==(const linear_congruential& __lhs, |
| const linear_congruential& __rhs) |
| { return __lhs._M_x == __rhs._M_x; } |
| |
| /** |
| * Compares two linear congruential random number generator |
| * objects of the same type for inequality. |
| * |
| * @param __lhs A linear congruential random number generator object. |
| * @param __rhs Another linear congruential random number generator obj. |
| * |
| * @returns true if the two objects are not equal, false otherwise. |
| */ |
| friend bool |
| operator!=(const linear_congruential& __lhs, |
| const linear_congruential& __rhs) |
| { return !(__lhs == __rhs); } |
| |
| /** |
| * Writes the textual representation of the state x(i) of x to @p __os. |
| * |
| * @param __os The output stream. |
| * @param __lcr A % linear_congruential random number generator. |
| * @returns __os. |
| */ |
| template<class _UIntType1, _UIntType1 __a1, _UIntType1 __c1, |
| _UIntType1 __m1, |
| typename _CharT, typename _Traits> |
| friend std::basic_ostream<_CharT, _Traits>& |
| operator<<(std::basic_ostream<_CharT, _Traits>& __os, |
| const linear_congruential<_UIntType1, __a1, __c1, |
| __m1>& __lcr); |
| |
| /** |
| * Sets the state of the engine by reading its textual |
| * representation from @p __is. |
| * |
| * The textual representation must have been previously written using an |
| * output stream whose imbued locale and whose type's template |
| * specialization arguments _CharT and _Traits were the same as those of |
| * @p __is. |
| * |
| * @param __is The input stream. |
| * @param __lcr A % linear_congruential random number generator. |
| * @returns __is. |
| */ |
| template<class _UIntType1, _UIntType1 __a1, _UIntType1 __c1, |
| _UIntType1 __m1, |
| typename _CharT, typename _Traits> |
| friend std::basic_istream<_CharT, _Traits>& |
| operator>>(std::basic_istream<_CharT, _Traits>& __is, |
| linear_congruential<_UIntType1, __a1, __c1, __m1>& __lcr); |
| |
| private: |
| template<class _Gen> |
| void |
| seed(_Gen& __g, true_type) |
| { return seed(static_cast<unsigned long>(__g)); } |
| |
| template<class _Gen> |
| void |
| seed(_Gen& __g, false_type); |
| |
| _UIntType _M_x; |
| }; |
| |
| /** |
| * The classic Minimum Standard rand0 of Lewis, Goodman, and Miller. |
| */ |
| typedef linear_congruential<unsigned long, 16807, 0, 2147483647> minstd_rand0; |
| |
| /** |
| * An alternative LCR (Lehmer Generator function) . |
| */ |
| typedef linear_congruential<unsigned long, 48271, 0, 2147483647> minstd_rand; |
| |
| |
| /** |
| * A generalized feedback shift register discrete random number generator. |
| * |
| * This algorithm avoids multiplication and division and is designed to be |
| * friendly to a pipelined architecture. If the parameters are chosen |
| * correctly, this generator will produce numbers with a very long period and |
| * fairly good apparent entropy, although still not cryptographically strong. |
| * |
| * The best way to use this generator is with the predefined mt19937 class. |
| * |
| * This algorithm was originally invented by Makoto Matsumoto and |
| * Takuji Nishimura. |
| * |
| * @var word_size The number of bits in each element of the state vector. |
| * @var state_size The degree of recursion. |
| * @var shift_size The period parameter. |
| * @var mask_bits The separation point bit index. |
| * @var parameter_a The last row of the twist matrix. |
| * @var output_u The first right-shift tempering matrix parameter. |
| * @var output_s The first left-shift tempering matrix parameter. |
| * @var output_b The first left-shift tempering matrix mask. |
| * @var output_t The second left-shift tempering matrix parameter. |
| * @var output_c The second left-shift tempering matrix mask. |
| * @var output_l The second right-shift tempering matrix parameter. |
| */ |
| template<class _UIntType, int __w, int __n, int __m, int __r, |
| _UIntType __a, int __u, int __s, _UIntType __b, int __t, |
| _UIntType __c, int __l> |
| class mersenne_twister |
| { |
| __glibcxx_class_requires(_UIntType, _UnsignedIntegerConcept) |
| |
| public: |
| // types |
| typedef _UIntType result_type; |
| |
| // parameter values |
| static const int word_size = __w; |
| static const int state_size = __n; |
| static const int shift_size = __m; |
| static const int mask_bits = __r; |
| static const _UIntType parameter_a = __a; |
| static const int output_u = __u; |
| static const int output_s = __s; |
| static const _UIntType output_b = __b; |
| static const int output_t = __t; |
| static const _UIntType output_c = __c; |
| static const int output_l = __l; |
| |
| // constructors and member function |
| mersenne_twister() |
| { seed(); } |
| |
| explicit |
| mersenne_twister(unsigned long __value) |
| { seed(__value); } |
| |
| template<class _Gen> |
| mersenne_twister(_Gen& __g) |
| { seed(__g); } |
| |
| void |
| seed() |
| { seed(5489UL); } |
| |
| void |
| seed(unsigned long __value); |
| |
| template<class _Gen> |
| void |
| seed(_Gen& __g) |
| { seed(__g, typename is_fundamental<_Gen>::type()); } |
| |
| result_type |
| min() const |
| { return 0; }; |
| |
| result_type |
| max() const |
| { return __detail::_Shift<_UIntType, __w>::__value - 1; } |
| |
| result_type |
| operator()(); |
| |
| /** |
| * Compares two % mersenne_twister random number generator objects of |
| * the same type for equality. |
| * |
| * @param __lhs A % mersenne_twister random number generator object. |
| * @param __rhs Another % mersenne_twister random number generator |
| * object. |
| * |
| * @returns true if the two objects are equal, false otherwise. |
| */ |
| friend bool |
| operator==(const mersenne_twister& __lhs, |
| const mersenne_twister& __rhs) |
| { return std::equal(__lhs._M_x, __lhs._M_x + state_size, __rhs._M_x); } |
| |
| /** |
| * Compares two % mersenne_twister random number generator objects of |
| * the same type for inequality. |
| * |
| * @param __lhs A % mersenne_twister random number generator object. |
| * @param __rhs Another % mersenne_twister random number generator |
| * object. |
| * |
| * @returns true if the two objects are not equal, false otherwise. |
| */ |
| friend bool |
| operator!=(const mersenne_twister& __lhs, |
| const mersenne_twister& __rhs) |
| { return !(__lhs == __rhs); } |
| |
| /** |
| * Inserts the current state of a % mersenne_twister random number |
| * generator engine @p __x into the output stream @p __os. |
| * |
| * @param __os An output stream. |
| * @param __x A % mersenne_twister random number generator engine. |
| * |
| * @returns The output stream with the state of @p __x inserted or in |
| * an error state. |
| */ |
| template<class _UIntType1, int __w1, int __n1, int __m1, int __r1, |
| _UIntType1 __a1, int __u1, int __s1, _UIntType1 __b1, int __t1, |
| _UIntType1 __c1, int __l1, |
| typename _CharT, typename _Traits> |
| friend std::basic_ostream<_CharT, _Traits>& |
| operator<<(std::basic_ostream<_CharT, _Traits>& __os, |
| const mersenne_twister<_UIntType1, __w1, __n1, __m1, __r1, |
| __a1, __u1, __s1, __b1, __t1, __c1, __l1>& __x); |
| |
| /** |
| * Extracts the current state of a % mersenne_twister random number |
| * generator engine @p __x from the input stream @p __is. |
| * |
| * @param __is An input stream. |
| * @param __x A % mersenne_twister random number generator engine. |
| * |
| * @returns The input stream with the state of @p __x extracted or in |
| * an error state. |
| */ |
| template<class _UIntType1, int __w1, int __n1, int __m1, int __r1, |
| _UIntType1 __a1, int __u1, int __s1, _UIntType1 __b1, int __t1, |
| _UIntType1 __c1, int __l1, |
| typename _CharT, typename _Traits> |
| friend std::basic_istream<_CharT, _Traits>& |
| operator>>(std::basic_istream<_CharT, _Traits>& __is, |
| mersenne_twister<_UIntType1, __w1, __n1, __m1, __r1, |
| __a1, __u1, __s1, __b1, __t1, __c1, __l1>& __x); |
| |
| private: |
| template<class _Gen> |
| void |
| seed(_Gen& __g, true_type) |
| { return seed(static_cast<unsigned long>(__g)); } |
| |
| template<class _Gen> |
| void |
| seed(_Gen& __g, false_type); |
| |
| _UIntType _M_x[state_size]; |
| int _M_p; |
| }; |
| |
| /** |
| * The classic Mersenne Twister. |
| * |
| * Reference: |
| * M. Matsumoto and T. Nishimura, "Mersenne Twister: A 623-Dimensionally |
| * Equidistributed Uniform Pseudo-Random Number Generator", ACM Transactions |
| * on Modeling and Computer Simulation, Vol. 8, No. 1, January 1998, pp 3-30. |
| */ |
| typedef mersenne_twister< |
| unsigned long, 32, 624, 397, 31, |
| 0x9908b0dful, 11, 7, |
| 0x9d2c5680ul, 15, |
| 0xefc60000ul, 18 |
| > mt19937; |
| |
| |
| /** |
| * @brief The Marsaglia-Zaman generator. |
| * |
| * This is a model of a Generalized Fibonacci discrete random number |
| * generator, sometimes referred to as the SWC generator. |
| * |
| * A discrete random number generator that produces pseudorandom |
| * numbers using @f$x_{i}\leftarrow(x_{i - s} - x_{i - r} - |
| * carry_{i-1}) \bmod m @f$. |
| * |
| * The size of the state is @f$ r @f$ |
| * and the maximum period of the generator is @f$ m^r - m^s -1 @f$. |
| * |
| * N1688[4.13] says "the template parameter _IntType shall denote an integral |
| * type large enough to store values up to m." |
| * |
| * @var _M_x The state of the generator. This is a ring buffer. |
| * @var _M_carry The carry. |
| * @var _M_p Current index of x(i - r). |
| */ |
| template<typename _IntType, _IntType __m, int __s, int __r> |
| class subtract_with_carry |
| { |
| __glibcxx_class_requires(_IntType, _IntegerConcept) |
| |
| public: |
| /** The type of the generated random value. */ |
| typedef _IntType result_type; |
| |
| // parameter values |
| static const _IntType modulus = __m; |
| static const int long_lag = __r; |
| static const int short_lag = __s; |
| |
| /** |
| * Constructs a default-initialized % subtract_with_carry random number |
| * generator. |
| */ |
| subtract_with_carry() |
| { this->seed(); } |
| |
| /** |
| * Constructs an explicitly seeded % subtract_with_carry random number |
| * generator. |
| */ |
| explicit |
| subtract_with_carry(unsigned long __value) |
| { this->seed(__value); } |
| |
| /** |
| * Constructs a %subtract_with_carry random number generator engine |
| * seeded from the generator function @p __g. |
| * |
| * @param __g The seed generator function. |
| */ |
| template<class _Gen> |
| subtract_with_carry(_Gen& __g) |
| { this->seed(__g); } |
| |
| /** |
| * Seeds the initial state @f$ x_0 @f$ of the random number generator. |
| * |
| * N1688[4.19] modifies this as follows. If @p __value == 0, |
| * sets value to 19780503. In any case, with a linear |
| * congruential generator lcg(i) having parameters @f$ m_{lcg} = |
| * 2147483563, a_{lcg} = 40014, c_{lcg} = 0, and lcg(0) = value |
| * @f$, sets @f$ x_{-r} \dots x_{-1} @f$ to @f$ lcg(1) \bmod m |
| * \dots lcg(r) \bmod m @f$ respectively. If @f$ x_{-1} = 0 @f$ |
| * set carry to 1, otherwise sets carry to 0. |
| */ |
| void |
| seed(unsigned long __value = 19780503); |
| |
| /** |
| * Seeds the initial state @f$ x_0 @f$ of the % subtract_with_carry |
| * random number generator. |
| */ |
| template<class _Gen> |
| void |
| seed(_Gen& __g) |
| { seed(__g, typename is_fundamental<_Gen>::type()); } |
| |
| /** |
| * Gets the inclusive minimum value of the range of random integers |
| * returned by this generator. |
| */ |
| result_type |
| min() const |
| { return 0; } |
| |
| /** |
| * Gets the inclusive maximum value of the range of random integers |
| * returned by this generator. |
| */ |
| result_type |
| max() const |
| { return this->modulus - 1; } |
| |
| /** |
| * Gets the next random number in the sequence. |
| */ |
| result_type |
| operator()(); |
| |
| /** |
| * Compares two % subtract_with_carry random number generator objects of |
| * the same type for equality. |
| * |
| * @param __lhs A % subtract_with_carry random number generator object. |
| * @param __rhs Another % subtract_with_carry random number generator |
| * object. |
| * |
| * @returns true if the two objects are equal, false otherwise. |
| */ |
| friend bool |
| operator==(const subtract_with_carry& __lhs, |
| const subtract_with_carry& __rhs) |
| { return std::equal(__lhs._M_x, __lhs._M_x + long_lag, __rhs._M_x); } |
| |
| /** |
| * Compares two % subtract_with_carry random number generator objects of |
| * the same type for inequality. |
| * |
| * @param __lhs A % subtract_with_carry random number generator object. |
| * @param __rhs Another % subtract_with_carry random number generator |
| * object. |
| * |
| * @returns true if the two objects are not equal, false otherwise. |
| */ |
| friend bool |
| operator!=(const subtract_with_carry& __lhs, |
| const subtract_with_carry& __rhs) |
| { return !(__lhs == __rhs); } |
| |
| /** |
| * Inserts the current state of a % subtract_with_carry random number |
| * generator engine @p __x into the output stream @p __os. |
| * |
| * @param __os An output stream. |
| * @param __x A % subtract_with_carry random number generator engine. |
| * |
| * @returns The output stream with the state of @p __x inserted or in |
| * an error state. |
| */ |
| template<typename _IntType1, _IntType1 __m1, int __s1, int __r1, |
| typename _CharT, typename _Traits> |
| friend std::basic_ostream<_CharT, _Traits>& |
| operator<<(std::basic_ostream<_CharT, _Traits>& __os, |
| const subtract_with_carry<_IntType1, __m1, __s1, |
| __r1>& __x); |
| |
| /** |
| * Extracts the current state of a % subtract_with_carry random number |
| * generator engine @p __x from the input stream @p __is. |
| * |
| * @param __is An input stream. |
| * @param __x A % subtract_with_carry random number generator engine. |
| * |
| * @returns The input stream with the state of @p __x extracted or in |
| * an error state. |
| */ |
| template<typename _IntType1, _IntType1 __m1, int __s1, int __r1, |
| typename _CharT, typename _Traits> |
| friend std::basic_istream<_CharT, _Traits>& |
| operator>>(std::basic_istream<_CharT, _Traits>& __is, |
| subtract_with_carry<_IntType1, __m1, __s1, __r1>& __x); |
| |
| private: |
| template<class _Gen> |
| void |
| seed(_Gen& __g, true_type) |
| { return seed(static_cast<unsigned long>(__g)); } |
| |
| template<class _Gen> |
| void |
| seed(_Gen& __g, false_type); |
| |
| typedef typename __gnu_cxx::__add_unsigned<_IntType>::__type _UIntType; |
| |
| _UIntType _M_x[long_lag]; |
| _UIntType _M_carry; |
| int _M_p; |
| }; |
| |
| |
| /** |
| * @brief The Marsaglia-Zaman generator (floats version). |
| * |
| * @var _M_x The state of the generator. This is a ring buffer. |
| * @var _M_carry The carry. |
| * @var _M_p Current index of x(i - r). |
| * @var _M_npows Precomputed negative powers of 2. |
| */ |
| template<typename _RealType, int __w, int __s, int __r> |
| class subtract_with_carry_01 |
| { |
| public: |
| /** The type of the generated random value. */ |
| typedef _RealType result_type; |
| |
| // parameter values |
| static const int word_size = __w; |
| static const int long_lag = __r; |
| static const int short_lag = __s; |
| |
| /** |
| * Constructs a default-initialized % subtract_with_carry_01 random |
| * number generator. |
| */ |
| subtract_with_carry_01() |
| { |
| this->seed(); |
| _M_initialize_npows(); |
| } |
| |
| /** |
| * Constructs an explicitly seeded % subtract_with_carry_01 random number |
| * generator. |
| */ |
| explicit |
| subtract_with_carry_01(unsigned long __value) |
| { |
| this->seed(__value); |
| _M_initialize_npows(); |
| } |
| |
| /** |
| * Constructs a % subtract_with_carry_01 random number generator engine |
| * seeded from the generator function @p __g. |
| * |
| * @param __g The seed generator function. |
| */ |
| template<class _Gen> |
| subtract_with_carry_01(_Gen& __g) |
| { |
| this->seed(__g); |
| _M_initialize_npows(); |
| } |
| |
| /** |
| * Seeds the initial state @f$ x_0 @f$ of the random number generator. |
| */ |
| void |
| seed(unsigned long __value = 19780503); |
| |
| /** |
| * Seeds the initial state @f$ x_0 @f$ of the % subtract_with_carry_01 |
| * random number generator. |
| */ |
| template<class _Gen> |
| void |
| seed(_Gen& __g) |
| { seed(__g, typename is_fundamental<_Gen>::type()); } |
| |
| /** |
| * Gets the minimum value of the range of random floats |
| * returned by this generator. |
| */ |
| result_type |
| min() const |
| { return 0.0; } |
| |
| /** |
| * Gets the maximum value of the range of random floats |
| * returned by this generator. |
| */ |
| result_type |
| max() const |
| { return 1.0; } |
| |
| /** |
| * Gets the next random number in the sequence. |
| */ |
| result_type |
| operator()(); |
| |
| /** |
| * Compares two % subtract_with_carry_01 random number generator objects |
| * of the same type for equality. |
| * |
| * @param __lhs A % subtract_with_carry_01 random number |
| * generator object. |
| * @param __rhs Another % subtract_with_carry_01 random number generator |
| * object. |
| * |
| * @returns true if the two objects are equal, false otherwise. |
| */ |
| friend bool |
| operator==(const subtract_with_carry_01& __lhs, |
| const subtract_with_carry_01& __rhs) |
| { |
| for (int __i = 0; __i < long_lag; ++__i) |
| if (!std::equal(__lhs._M_x[__i], __lhs._M_x[__i] + __n, |
| __rhs._M_x[__i])) |
| return false; |
| return true; |
| } |
| |
| /** |
| * Compares two % subtract_with_carry_01 random number generator objects |
| * of the same type for inequality. |
| * |
| * @param __lhs A % subtract_with_carry_01 random number |
| * generator object. |
| * |
| * @param __rhs Another % subtract_with_carry_01 random number generator |
| * object. |
| * |
| * @returns true if the two objects are not equal, false otherwise. |
| */ |
| friend bool |
| operator!=(const subtract_with_carry_01& __lhs, |
| const subtract_with_carry_01& __rhs) |
| { return !(__lhs == __rhs); } |
| |
| /** |
| * Inserts the current state of a % subtract_with_carry_01 random number |
| * generator engine @p __x into the output stream @p __os. |
| * |
| * @param __os An output stream. |
| * @param __x A % subtract_with_carry_01 random number generator engine. |
| * |
| * @returns The output stream with the state of @p __x inserted or in |
| * an error state. |
| */ |
| template<typename _RealType1, int __w1, int __s1, int __r1, |
| typename _CharT, typename _Traits> |
| friend std::basic_ostream<_CharT, _Traits>& |
| operator<<(std::basic_ostream<_CharT, _Traits>& __os, |
| const subtract_with_carry_01<_RealType1, __w1, __s1, |
| __r1>& __x); |
| |
| /** |
| * Extracts the current state of a % subtract_with_carry_01 random number |
| * generator engine @p __x from the input stream @p __is. |
| * |
| * @param __is An input stream. |
| * @param __x A % subtract_with_carry_01 random number generator engine. |
| * |
| * @returns The input stream with the state of @p __x extracted or in |
| * an error state. |
| */ |
| template<typename _RealType1, int __w1, int __s1, int __r1, |
| typename _CharT, typename _Traits> |
| friend std::basic_istream<_CharT, _Traits>& |
| operator>>(std::basic_istream<_CharT, _Traits>& __is, |
| subtract_with_carry_01<_RealType1, __w1, __s1, __r1>& __x); |
| |
| private: |
| template<class _Gen> |
| void |
| seed(_Gen& __g, true_type) |
| { return seed(static_cast<unsigned long>(__g)); } |
| |
| template<class _Gen> |
| void |
| seed(_Gen& __g, false_type); |
| |
| void |
| _M_initialize_npows(); |
| |
| static const int __n = (__w + 31) / 32; |
| |
| typedef __detail::_UInt32Type _UInt32Type; |
| _UInt32Type _M_x[long_lag][__n]; |
| _RealType _M_npows[__n]; |
| _UInt32Type _M_carry; |
| int _M_p; |
| }; |
| |
| typedef subtract_with_carry_01<float, 24, 10, 24> ranlux_base_01; |
| |
| // _GLIBCXX_RESOLVE_LIB_DEFECTS |
| // 508. Bad parameters for ranlux64_base_01. |
| typedef subtract_with_carry_01<double, 48, 5, 12> ranlux64_base_01; |
| |
| |
| /** |
| * Produces random numbers from some base engine by discarding blocks of |
| * data. |
| * |
| * 0 <= @p __r <= @p __p |
| */ |
| template<class _UniformRandomNumberGenerator, int __p, int __r> |
| class discard_block |
| { |
| // __glibcxx_class_requires(typename base_type::result_type, |
| // ArithmeticTypeConcept) |
| |
| public: |
| /** The type of the underlying generator engine. */ |
| typedef _UniformRandomNumberGenerator base_type; |
| /** The type of the generated random value. */ |
| typedef typename base_type::result_type result_type; |
| |
| // parameter values |
| static const int block_size = __p; |
| static const int used_block = __r; |
| |
| /** |
| * Constructs a default %discard_block engine. |
| * |
| * The underlying engine is default constructed as well. |
| */ |
| discard_block() |
| : _M_n(0) { } |
| |
| /** |
| * Copy constructs a %discard_block engine. |
| * |
| * Copies an existing base class random number generator. |
| * @param rng An existing (base class) engine object. |
| */ |
| explicit |
| discard_block(const base_type& __rng) |
| : _M_b(__rng), _M_n(0) { } |
| |
| /** |
| * Seed constructs a %discard_block engine. |
| * |
| * Constructs the underlying generator engine seeded with @p __s. |
| * @param __s A seed value for the base class engine. |
| */ |
| explicit |
| discard_block(unsigned long __s) |
| : _M_b(__s), _M_n(0) { } |
| |
| /** |
| * Generator construct a %discard_block engine. |
| * |
| * @param __g A seed generator function. |
| */ |
| template<class _Gen> |
| discard_block(_Gen& __g) |
| : _M_b(__g), _M_n(0) { } |
| |
| /** |
| * Reseeds the %discard_block object with the default seed for the |
| * underlying base class generator engine. |
| */ |
| void seed() |
| { |
| _M_b.seed(); |
| _M_n = 0; |
| } |
| |
| /** |
| * Reseeds the %discard_block object with the given seed generator |
| * function. |
| * @param __g A seed generator function. |
| */ |
| template<class _Gen> |
| void seed(_Gen& __g) |
| { |
| _M_b.seed(__g); |
| _M_n = 0; |
| } |
| |
| /** |
| * Gets a const reference to the underlying generator engine object. |
| */ |
| const base_type& |
| base() const |
| { return _M_b; } |
| |
| /** |
| * Gets the minimum value in the generated random number range. |
| */ |
| result_type |
| min() const |
| { return _M_b.min(); } |
| |
| /** |
| * Gets the maximum value in the generated random number range. |
| */ |
| result_type |
| max() const |
| { return _M_b.max(); } |
| |
| /** |
| * Gets the next value in the generated random number sequence. |
| */ |
| result_type |
| operator()(); |
| |
| /** |
| * Compares two %discard_block random number generator objects of |
| * the same type for equality. |
| * |
| * @param __lhs A %discard_block random number generator object. |
| * @param __rhs Another %discard_block random number generator |
| * object. |
| * |
| * @returns true if the two objects are equal, false otherwise. |
| */ |
| friend bool |
| operator==(const discard_block& __lhs, const discard_block& __rhs) |
| { return (__lhs._M_b == __rhs._M_b) && (__lhs._M_n == __rhs._M_n); } |
| |
| /** |
| * Compares two %discard_block random number generator objects of |
| * the same type for inequality. |
| * |
| * @param __lhs A %discard_block random number generator object. |
| * @param __rhs Another %discard_block random number generator |
| * object. |
| * |
| * @returns true if the two objects are not equal, false otherwise. |
| */ |
| friend bool |
| operator!=(const discard_block& __lhs, const discard_block& __rhs) |
| { return !(__lhs == __rhs); } |
| |
| /** |
| * Inserts the current state of a %discard_block random number |
| * generator engine @p __x into the output stream @p __os. |
| * |
| * @param __os An output stream. |
| * @param __x A %discard_block random number generator engine. |
| * |
| * @returns The output stream with the state of @p __x inserted or in |
| * an error state. |
| */ |
| template<class _UniformRandomNumberGenerator1, int __p1, int __r1, |
| typename _CharT, typename _Traits> |
| friend std::basic_ostream<_CharT, _Traits>& |
| operator<<(std::basic_ostream<_CharT, _Traits>& __os, |
| const discard_block<_UniformRandomNumberGenerator1, |
| __p1, __r1>& __x); |
| |
| /** |
| * Extracts the current state of a % subtract_with_carry random number |
| * generator engine @p __x from the input stream @p __is. |
| * |
| * @param __is An input stream. |
| * @param __x A %discard_block random number generator engine. |
| * |
| * @returns The input stream with the state of @p __x extracted or in |
| * an error state. |
| */ |
| template<class _UniformRandomNumberGenerator1, int __p1, int __r1, |
| typename _CharT, typename _Traits> |
| friend std::basic_istream<_CharT, _Traits>& |
| operator>>(std::basic_istream<_CharT, _Traits>& __is, |
| discard_block<_UniformRandomNumberGenerator1, |
| __p1, __r1>& __x); |
| |
| private: |
| base_type _M_b; |
| int _M_n; |
| }; |
| |
| |
| /** |
| * James's luxury-level-3 integer adaptation of Luescher's generator. |
| */ |
| typedef discard_block< |
| subtract_with_carry<unsigned long, (1UL << 24), 10, 24>, |
| 223, |
| 24 |
| > ranlux3; |
| |
| /** |
| * James's luxury-level-4 integer adaptation of Luescher's generator. |
| */ |
| typedef discard_block< |
| subtract_with_carry<unsigned long, (1UL << 24), 10, 24>, |
| 389, |
| 24 |
| > ranlux4; |
| |
| typedef discard_block< |
| subtract_with_carry_01<float, 24, 10, 24>, |
| 223, |
| 24 |
| > ranlux3_01; |
| |
| typedef discard_block< |
| subtract_with_carry_01<float, 24, 10, 24>, |
| 389, |
| 24 |
| > ranlux4_01; |
| |
| |
| /** |
| * A random number generator adaptor class that combines two random number |
| * generator engines into a single output sequence. |
| */ |
| template<class _UniformRandomNumberGenerator1, int __s1, |
| class _UniformRandomNumberGenerator2, int __s2> |
| class xor_combine |
| { |
| // __glibcxx_class_requires(typename _UniformRandomNumberGenerator1:: |
| // result_type, ArithmeticTypeConcept) |
| // __glibcxx_class_requires(typename _UniformRandomNumberGenerator2:: |
| // result_type, ArithmeticTypeConcept) |
| |
| public: |
| /** The type of the first underlying generator engine. */ |
| typedef _UniformRandomNumberGenerator1 base1_type; |
| /** The type of the second underlying generator engine. */ |
| typedef _UniformRandomNumberGenerator2 base2_type; |
| |
| private: |
| typedef typename base1_type::result_type _Result_type1; |
| typedef typename base2_type::result_type _Result_type2; |
| |
| public: |
| /** The type of the generated random value. */ |
| typedef typename __gnu_cxx::__conditional_type<(sizeof(_Result_type1) |
| > sizeof(_Result_type2)), |
| _Result_type1, _Result_type2>::__type result_type; |
| |
| // parameter values |
| static const int shift1 = __s1; |
| static const int shift2 = __s2; |
| |
| // constructors and member function |
| xor_combine() |
| : _M_b1(), _M_b2() |
| { _M_initialize_max(); } |
| |
| xor_combine(const base1_type& __rng1, const base2_type& __rng2) |
| : _M_b1(__rng1), _M_b2(__rng2) |
| { _M_initialize_max(); } |
| |
| xor_combine(unsigned long __s) |
| : _M_b1(__s), _M_b2(__s + 1) |
| { _M_initialize_max(); } |
| |
| template<class _Gen> |
| xor_combine(_Gen& __g) |
| : _M_b1(__g), _M_b2(__g) |
| { _M_initialize_max(); } |
| |
| void |
| seed() |
| { |
| _M_b1.seed(); |
| _M_b2.seed(); |
| } |
| |
| template<class _Gen> |
| void |
| seed(_Gen& __g) |
| { |
| _M_b1.seed(__g); |
| _M_b2.seed(__g); |
| } |
| |
| const base1_type& |
| base1() const |
| { return _M_b1; } |
| |
| const base2_type& |
| base2() const |
| { return _M_b2; } |
| |
| result_type |
| min() const |
| { return 0; } |
| |
| result_type |
| max() const |
| { return _M_max; } |
| |
| /** |
| * Gets the next random number in the sequence. |
| */ |
| // NB: Not exactly the TR1 formula, per N2079 instead. |
| result_type |
| operator()() |
| { |
| return ((result_type(_M_b1() - _M_b1.min()) << shift1) |
| ^ (result_type(_M_b2() - _M_b2.min()) << shift2)); |
| } |
| |
| /** |
| * Compares two %xor_combine random number generator objects of |
| * the same type for equality. |
| * |
| * @param __lhs A %xor_combine random number generator object. |
| * @param __rhs Another %xor_combine random number generator |
| * object. |
| * |
| * @returns true if the two objects are equal, false otherwise. |
| */ |
| friend bool |
| operator==(const xor_combine& __lhs, const xor_combine& __rhs) |
| { |
| return (__lhs.base1() == __rhs.base1()) |
| && (__lhs.base2() == __rhs.base2()); |
| } |
| |
| /** |
| * Compares two %xor_combine random number generator objects of |
| * the same type for inequality. |
| * |
| * @param __lhs A %xor_combine random number generator object. |
| * @param __rhs Another %xor_combine random number generator |
| * object. |
| * |
| * @returns true if the two objects are not equal, false otherwise. |
| */ |
| friend bool |
| operator!=(const xor_combine& __lhs, const xor_combine& __rhs) |
| { return !(__lhs == __rhs); } |
| |
| /** |
| * Inserts the current state of a %xor_combine random number |
| * generator engine @p __x into the output stream @p __os. |
| * |
| * @param __os An output stream. |
| * @param __x A %xor_combine random number generator engine. |
| * |
| * @returns The output stream with the state of @p __x inserted or in |
| * an error state. |
| */ |
| template<class _UniformRandomNumberGenerator11, int __s11, |
| class _UniformRandomNumberGenerator21, int __s21, |
| typename _CharT, typename _Traits> |
| friend std::basic_ostream<_CharT, _Traits>& |
| operator<<(std::basic_ostream<_CharT, _Traits>& __os, |
| const xor_combine<_UniformRandomNumberGenerator11, __s11, |
| _UniformRandomNumberGenerator21, __s21>& __x); |
| |
| /** |
| * Extracts the current state of a %xor_combine random number |
| * generator engine @p __x from the input stream @p __is. |
| * |
| * @param __is An input stream. |
| * @param __x A %xor_combine random number generator engine. |
| * |
| * @returns The input stream with the state of @p __x extracted or in |
| * an error state. |
| */ |
| template<class _UniformRandomNumberGenerator11, int __s11, |
| class _UniformRandomNumberGenerator21, int __s21, |
| typename _CharT, typename _Traits> |
| friend std::basic_istream<_CharT, _Traits>& |
| operator>>(std::basic_istream<_CharT, _Traits>& __is, |
| xor_combine<_UniformRandomNumberGenerator11, __s11, |
| _UniformRandomNumberGenerator21, __s21>& __x); |
| |
| private: |
| void |
| _M_initialize_max(); |
| |
| result_type |
| _M_initialize_max_aux(result_type, result_type, int); |
| |
| base1_type _M_b1; |
| base2_type _M_b2; |
| result_type _M_max; |
| }; |
| |
| |
| /** |
| * A standard interface to a platform-specific non-deterministic |
| * random number generator (if any are available). |
| */ |
| class random_device |
| { |
| public: |
| // types |
| typedef unsigned int result_type; |
| |
| // constructors, destructors and member functions |
| |
| #ifdef _GLIBCXX_USE_RANDOM_TR1 |
| |
| explicit |
| random_device(const std::string& __token = "/dev/urandom") |
| { |
| if ((__token != "/dev/urandom" && __token != "/dev/random") |
| || !(_M_file = std::fopen(__token.c_str(), "rb"))) |
| std::__throw_runtime_error(__N("random_device::" |
| "random_device(const std::string&)")); |
| } |
| |
| ~random_device() |
| { std::fclose(_M_file); } |
| |
| #else |
| |
| explicit |
| random_device(const std::string& __token = "mt19937") |
| : _M_mt(_M_strtoul(__token)) { } |
| |
| private: |
| static unsigned long |
| _M_strtoul(const std::string& __str) |
| { |
| unsigned long __ret = 5489UL; |
| if (__str != "mt19937") |
| { |
| const char* __nptr = __str.c_str(); |
| char* __endptr; |
| __ret = std::strtoul(__nptr, &__endptr, 0); |
| if (*__nptr == '\0' || *__endptr != '\0') |
| std::__throw_runtime_error(__N("random_device::_M_strtoul" |
| "(const std::string&)")); |
| } |
| return __ret; |
| } |
| |
| public: |
| |
| #endif |
| |
| result_type |
| min() const |
| { return std::numeric_limits<result_type>::min(); } |
| |
| result_type |
| max() const |
| { return std::numeric_limits<result_type>::max(); } |
| |
| double |
| entropy() const |
| { return 0.0; } |
| |
| result_type |
| operator()() |
| { |
| #ifdef _GLIBCXX_USE_RANDOM_TR1 |
| result_type __ret; |
| std::fread(reinterpret_cast<void*>(&__ret), sizeof(result_type), |
| 1, _M_file); |
| return __ret; |
| #else |
| return _M_mt(); |
| #endif |
| } |
| |
| private: |
| random_device(const random_device&); |
| void operator=(const random_device&); |
| |
| #ifdef _GLIBCXX_USE_RANDOM_TR1 |
| FILE* _M_file; |
| #else |
| mt19937 _M_mt; |
| #endif |
| }; |
| |
| /* @} */ // group tr1_random_generators |
| |
| /** |
| * @defgroup tr1_random_distributions Random Number Distributions |
| * @ingroup tr1_random |
| * @{ |
| */ |
| |
| /** |
| * @defgroup tr1_random_distributions_discrete Discrete Distributions |
| * @ingroup tr1_random_distributions |
| * @{ |
| */ |
| |
| /** |
| * @brief Uniform discrete distribution for random numbers. |
| * A discrete random distribution on the range @f$[min, max]@f$ with equal |
| * probability throughout the range. |
| */ |
| template<typename _IntType = int> |
| class uniform_int |
| { |
| __glibcxx_class_requires(_IntType, _IntegerConcept) |
| |
| public: |
| /** The type of the parameters of the distribution. */ |
| typedef _IntType input_type; |
| /** The type of the range of the distribution. */ |
| typedef _IntType result_type; |
| |
| public: |
| /** |
| * Constructs a uniform distribution object. |
| */ |
| explicit |
| uniform_int(_IntType __min = 0, _IntType __max = 9) |
| : _M_min(__min), _M_max(__max) |
| { |
| _GLIBCXX_DEBUG_ASSERT(_M_min <= _M_max); |
| } |
| |
| /** |
| * Gets the inclusive lower bound of the distribution range. |
| */ |
| result_type |
| min() const |
| { return _M_min; } |
| |
| /** |
| * Gets the inclusive upper bound of the distribution range. |
| */ |
| result_type |
| max() const |
| { return _M_max; } |
| |
| /** |
| * Resets the distribution state. |
| * |
| * Does nothing for the uniform integer distribution. |
| */ |
| void |
| reset() { } |
| |
| /** |
| * Gets a uniformly distributed random number in the range |
| * @f$(min, max)@f$. |
| */ |
| template<typename _UniformRandomNumberGenerator> |
| result_type |
| operator()(_UniformRandomNumberGenerator& __urng) |
| { |
| typedef typename _UniformRandomNumberGenerator::result_type |
| _UResult_type; |
| return _M_call(__urng, _M_min, _M_max, |
| typename is_integral<_UResult_type>::type()); |
| } |
| |
| /** |
| * Gets a uniform random number in the range @f$[0, n)@f$. |
| * |
| * This function is aimed at use with std::random_shuffle. |
| */ |
| template<typename _UniformRandomNumberGenerator> |
| result_type |
| operator()(_UniformRandomNumberGenerator& __urng, result_type __n) |
| { |
| typedef typename _UniformRandomNumberGenerator::result_type |
| _UResult_type; |
| return _M_call(__urng, 0, __n - 1, |
| typename is_integral<_UResult_type>::type()); |
| } |
| |
| /** |
| * Inserts a %uniform_int random number distribution @p __x into the |
| * output stream @p os. |
| * |
| * @param __os An output stream. |
| * @param __x A %uniform_int random number distribution. |
| * |
| * @returns The output stream with the state of @p __x inserted or in |
| * an error state. |
| */ |
| template<typename _IntType1, typename _CharT, typename _Traits> |
| friend std::basic_ostream<_CharT, _Traits>& |
| operator<<(std::basic_ostream<_CharT, _Traits>& __os, |
| const uniform_int<_IntType1>& __x); |
| |
| /** |
| * Extracts a %uniform_int random number distribution |
| * @p __x from the input stream @p __is. |
| * |
| * @param __is An input stream. |
| * @param __x A %uniform_int random number generator engine. |
| * |
| * @returns The input stream with @p __x extracted or in an error state. |
| */ |
| template<typename _IntType1, typename _CharT, typename _Traits> |
| friend std::basic_istream<_CharT, _Traits>& |
| operator>>(std::basic_istream<_CharT, _Traits>& __is, |
| uniform_int<_IntType1>& __x); |
| |
| private: |
| template<typename _UniformRandomNumberGenerator> |
| result_type |
| _M_call(_UniformRandomNumberGenerator& __urng, |
| result_type __min, result_type __max, true_type); |
| |
| template<typename _UniformRandomNumberGenerator> |
| result_type |
| _M_call(_UniformRandomNumberGenerator& __urng, |
| result_type __min, result_type __max, false_type) |
| { |
| return result_type((__urng() - __urng.min()) |
| / (__urng.max() - __urng.min()) |
| * (__max - __min + 1)) + __min; |
| } |
| |
| _IntType _M_min; |
| _IntType _M_max; |
| }; |
| |
| |
| /** |
| * @brief A Bernoulli random number distribution. |
| * |
| * Generates a sequence of true and false values with likelihood @f$ p @f$ |
| * that true will come up and @f$ (1 - p) @f$ that false will appear. |
| */ |
| class bernoulli_distribution |
| { |
| public: |
| typedef int input_type; |
| typedef bool result_type; |
| |
| public: |
| /** |
| * Constructs a Bernoulli distribution with likelihood @p p. |
| * |
| * @param __p [IN] The likelihood of a true result being returned. Must |
| * be in the interval @f$ [0, 1] @f$. |
| */ |
| explicit |
| bernoulli_distribution(double __p = 0.5) |
| : _M_p(__p) |
| { |
| _GLIBCXX_DEBUG_ASSERT((_M_p >= 0.0) && (_M_p <= 1.0)); |
| } |
| |
| /** |
| * Gets the @p p parameter of the distribution. |
| */ |
| double |
| p() const |
| { return _M_p; } |
| |
| /** |
| * Resets the distribution state. |
| * |
| * Does nothing for a Bernoulli distribution. |
| */ |
| void |
| reset() { } |
| |
| /** |
| * Gets the next value in the Bernoullian sequence. |
| */ |
| template<class _UniformRandomNumberGenerator> |
| result_type |
| operator()(_UniformRandomNumberGenerator& __urng) |
| { |
| if ((__urng() - __urng.min()) < _M_p * (__urng.max() - __urng.min())) |
| return true; |
| return false; |
| } |
| |
| /** |
| * Inserts a %bernoulli_distribution random number distribution |
| * @p __x into the output stream @p __os. |
| * |
| * @param __os An output stream. |
| * @param __x A %bernoulli_distribution random number distribution. |
| * |
| * @returns The output stream with the state of @p __x inserted or in |
| * an error state. |
| */ |
| template<typename _CharT, typename _Traits> |
| friend std::basic_ostream<_CharT, _Traits>& |
| operator<<(std::basic_ostream<_CharT, _Traits>& __os, |
| const bernoulli_distribution& __x); |
| |
| /** |
| * Extracts a %bernoulli_distribution random number distribution |
| * @p __x from the input stream @p __is. |
| * |
| * @param __is An input stream. |
| * @param __x A %bernoulli_distribution random number generator engine. |
| * |
| * @returns The input stream with @p __x extracted or in an error state. |
| */ |
| template<typename _CharT, typename _Traits> |
| friend std::basic_istream<_CharT, _Traits>& |
| operator>>(std::basic_istream<_CharT, _Traits>& __is, |
| bernoulli_distribution& __x) |
| { return __is >> __x._M_p; } |
| |
| private: |
| double _M_p; |
| }; |
| |
| |
| /** |
| * @brief A discrete geometric random number distribution. |
| * |
| * The formula for the geometric probability mass function is |
| * @f$ p(i) = (1 - p)p^{i-1} @f$ where @f$ p @f$ is the parameter of the |
| * distribution. |
| */ |
| template<typename _IntType = int, typename _RealType = double> |
| class geometric_distribution |
| { |
| public: |
| // types |
| typedef _RealType input_type; |
| typedef _IntType result_type; |
| |
| // constructors and member function |
| explicit |
| geometric_distribution(const _RealType& __p = _RealType(0.5)) |
| : _M_p(__p) |
| { |
| _GLIBCXX_DEBUG_ASSERT((_M_p > 0.0) && (_M_p < 1.0)); |
| _M_initialize(); |
| } |
| |
| /** |
| * Gets the distribution parameter @p p. |
| */ |
| _RealType |
| p() const |
| { return _M_p; } |
| |
| void |
| reset() { } |
| |
| template<class _UniformRandomNumberGenerator> |
| result_type |
| operator()(_UniformRandomNumberGenerator& __urng); |
| |
| /** |
| * Inserts a %geometric_distribution random number distribution |
| * @p __x into the output stream @p __os. |
| * |
| * @param __os An output stream. |
| * @param __x A %geometric_distribution random number distribution. |
| * |
| * @returns The output stream with the state of @p __x inserted or in |
| * an error state. |
| */ |
| template<typename _IntType1, typename _RealType1, |
| typename _CharT, typename _Traits> |
| friend std::basic_ostream<_CharT, _Traits>& |
| operator<<(std::basic_ostream<_CharT, _Traits>& __os, |
| const geometric_distribution<_IntType1, _RealType1>& __x); |
| |
| /** |
| * Extracts a %geometric_distribution random number distribution |
| * @p __x from the input stream @p __is. |
| * |
| * @param __is An input stream. |
| * @param __x A %geometric_distribution random number generator engine. |
| * |
| * @returns The input stream with @p __x extracted or in an error state. |
| */ |
| template<typename _CharT, typename _Traits> |
| friend std::basic_istream<_CharT, _Traits>& |
| operator>>(std::basic_istream<_CharT, _Traits>& __is, |
| geometric_distribution& __x) |
| { |
| __is >> __x._M_p; |
| __x._M_initialize(); |
| return __is; |
| } |
| |
| private: |
| void |
| _M_initialize() |
| { _M_log_p = std::log(_M_p); } |
| |
| _RealType _M_p; |
| _RealType _M_log_p; |
| }; |
| |
| |
| template<typename _RealType> |
| class normal_distribution; |
| |
| /** |
| * @brief A discrete Poisson random number distribution. |
| * |
| * The formula for the Poisson probability mass function is |
| * @f$ p(i) = \frac{mean^i}{i!} e^{-mean} @f$ where @f$ mean @f$ is the |
| * parameter of the distribution. |
| */ |
| template<typename _IntType = int, typename _RealType = double> |
| class poisson_distribution |
| { |
| public: |
| // types |
| typedef _RealType input_type; |
| typedef _IntType result_type; |
| |
| // constructors and member function |
| explicit |
| poisson_distribution(const _RealType& __mean = _RealType(1)) |
| : _M_mean(__mean), _M_nd() |
| { |
| _GLIBCXX_DEBUG_ASSERT(_M_mean > 0.0); |
| _M_initialize(); |
| } |
| |
| /** |
| * Gets the distribution parameter @p mean. |
| */ |
| _RealType |
| mean() const |
| { return _M_mean; } |
| |
| void |
| reset() |
| { _M_nd.reset(); } |
| |
| template<class _UniformRandomNumberGenerator> |
| result_type |
| operator()(_UniformRandomNumberGenerator& __urng); |
| |
| /** |
| * Inserts a %poisson_distribution random number distribution |
| * @p __x into the output stream @p __os. |
| * |
| * @param __os An output stream. |
| * @param __x A %poisson_distribution random number distribution. |
| * |
| * @returns The output stream with the state of @p __x inserted or in |
| * an error state. |
| */ |
| template<typename _IntType1, typename _RealType1, |
| typename _CharT, typename _Traits> |
| friend std::basic_ostream<_CharT, _Traits>& |
| operator<<(std::basic_ostream<_CharT, _Traits>& __os, |
| const poisson_distribution<_IntType1, _RealType1>& __x); |
| |
| /** |
| * Extracts a %poisson_distribution random number distribution |
| * @p __x from the input stream @p __is. |
| * |
| * @param __is An input stream. |
| * @param __x A %poisson_distribution random number generator engine. |
| * |
| * @returns The input stream with @p __x extracted or in an error state. |
| */ |
| template<typename _IntType1, typename _RealType1, |
| typename _CharT, typename _Traits> |
| friend std::basic_istream<_CharT, _Traits>& |
| operator>>(std::basic_istream<_CharT, _Traits>& __is, |
| poisson_distribution<_IntType1, _RealType1>& __x); |
| |
| private: |
| void |
| _M_initialize(); |
| |
| // NB: Unused when _GLIBCXX_USE_C99_MATH_TR1 is undefined. |
| normal_distribution<_RealType> _M_nd; |
| |
| _RealType _M_mean; |
| |
| // Hosts either log(mean) or the threshold of the simple method. |
| _RealType _M_lm_thr; |
| #if _GLIBCXX_USE_C99_MATH_TR1 |
| _RealType _M_lfm, _M_sm, _M_d, _M_scx, _M_1cx, _M_c2b, _M_cb; |
| #endif |
| }; |
| |
| |
| /** |
| * @brief A discrete binomial random number distribution. |
| * |
| * The formula for the binomial probability mass function is |
| * @f$ p(i) = \binom{n}{i} p^i (1 - p)^{t - i} @f$ where @f$ t @f$ |
| * and @f$ p @f$ are the parameters of the distribution. |
| */ |
| template<typename _IntType = int, typename _RealType = double> |
| class binomial_distribution |
| { |
| public: |
| // types |
| typedef _RealType input_type; |
| typedef _IntType result_type; |
| |
| // constructors and member function |
| explicit |
| binomial_distribution(_IntType __t = 1, |
| const _RealType& __p = _RealType(0.5)) |
| : _M_t(__t), _M_p(__p), _M_nd() |
| { |
| _GLIBCXX_DEBUG_ASSERT((_M_t >= 0) && (_M_p >= 0.0) && (_M_p <= 1.0)); |
| _M_initialize(); |
| } |
| |
| /** |
| * Gets the distribution @p t parameter. |
| */ |
| _IntType |
| t() const |
| { return _M_t; } |
| |
| /** |
| * Gets the distribution @p p parameter. |
| */ |
| _RealType |
| p() const |
| { return _M_p; } |
| |
| void |
| reset() |
| { _M_nd.reset(); } |
| |
| template<class _UniformRandomNumberGenerator> |
| result_type |
| operator()(_UniformRandomNumberGenerator& __urng); |
| |
| /** |
| * Inserts a %binomial_distribution random number distribution |
| * @p __x into the output stream @p __os. |
| * |
| * @param __os An output stream. |
| * @param __x A %binomial_distribution random number distribution. |
| * |
| * @returns The output stream with the state of @p __x inserted or in |
| * an error state. |
| */ |
| template<typename _IntType1, typename _RealType1, |
| typename _CharT, typename _Traits> |
| friend std::basic_ostream<_CharT, _Traits>& |
| operator<<(std::basic_ostream<_CharT, _Traits>& __os, |
| const binomial_distribution<_IntType1, _RealType1>& __x); |
| |
| /** |
| * Extracts a %binomial_distribution random number distribution |
| * @p __x from the input stream @p __is. |
| * |
| * @param __is An input stream. |
| * @param __x A %binomial_distribution random number generator engine. |
| * |
| * @returns The input stream with @p __x extracted or in an error state. |
| */ |
| template<typename _IntType1, typename _RealType1, |
| typename _CharT, typename _Traits> |
| friend std::basic_istream<_CharT, _Traits>& |
| operator>>(std::basic_istream<_CharT, _Traits>& __is, |
| binomial_distribution<_IntType1, _RealType1>& __x); |
| |
| private: |
| void |
| _M_initialize(); |
| |
| template<class _UniformRandomNumberGenerator> |
| result_type |
| _M_waiting(_UniformRandomNumberGenerator& __urng, _IntType __t); |
| |
| // NB: Unused when _GLIBCXX_USE_C99_MATH_TR1 is undefined. |
| normal_distribution<_RealType> _M_nd; |
| |
| _RealType _M_q; |
| #if _GLIBCXX_USE_C99_MATH_TR1 |
| _RealType _M_d1, _M_d2, _M_s1, _M_s2, _M_c, |
| _M_a1, _M_a123, _M_s, _M_lf, _M_lp1p; |
| #endif |
| _RealType _M_p; |
| _IntType _M_t; |
| |
| bool _M_easy; |
| }; |
| |
| /* @} */ // group tr1_random_distributions_discrete |
| |
| /** |
| * @defgroup tr1_random_distributions_continuous Continuous Distributions |
| * @ingroup tr1_random_distributions |
| * @{ |
| */ |
| |
| /** |
| * @brief Uniform continuous distribution for random numbers. |
| * |
| * A continuous random distribution on the range [min, max) with equal |
| * probability throughout the range. The URNG should be real-valued and |
| * deliver number in the range [0, 1). |
| */ |
| template<typename _RealType = double> |
| class uniform_real |
| { |
| public: |
| // types |
| typedef _RealType input_type; |
| typedef _RealType result_type; |
| |
| public: |
| /** |
| * Constructs a uniform_real object. |
| * |
| * @param __min [IN] The lower bound of the distribution. |
| * @param __max [IN] The upper bound of the distribution. |
| */ |
| explicit |
| uniform_real(_RealType __min = _RealType(0), |
| _RealType __max = _RealType(1)) |
| : _M_min(__min), _M_max(__max) |
| { |
| _GLIBCXX_DEBUG_ASSERT(_M_min <= _M_max); |
| } |
| |
| result_type |
| min() const |
| { return _M_min; } |
| |
| result_type |
| max() const |
| { return _M_max; } |
| |
| void |
| reset() { } |
| |
| template<class _UniformRandomNumberGenerator> |
| result_type |
| operator()(_UniformRandomNumberGenerator& __urng) |
| { return (__urng() * (_M_max - _M_min)) + _M_min; } |
| |
| /** |
| * Inserts a %uniform_real random number distribution @p __x into the |
| * output stream @p __os. |
| * |
| * @param __os An output stream. |
| * @param __x A %uniform_real random number distribution. |
| * |
| * @returns The output stream with the state of @p __x inserted or in |
| * an error state. |
| */ |
| template<typename _RealType1, typename _CharT, typename _Traits> |
| friend std::basic_ostream<_CharT, _Traits>& |
| operator<<(std::basic_ostream<_CharT, _Traits>& __os, |
| const uniform_real<_RealType1>& __x); |
| |
| /** |
| * Extracts a %uniform_real random number distribution |
| * @p __x from the input stream @p __is. |
| * |
| * @param __is An input stream. |
| * @param __x A %uniform_real random number generator engine. |
| * |
| * @returns The input stream with @p __x extracted or in an error state. |
| */ |
| template<typename _RealType1, typename _CharT, typename _Traits> |
| friend std::basic_istream<_CharT, _Traits>& |
| operator>>(std::basic_istream<_CharT, _Traits>& __is, |
| uniform_real<_RealType1>& __x); |
| |
| private: |
| _RealType _M_min; |
| _RealType _M_max; |
| }; |
| |
| |
| /** |
| * @brief An exponential continuous distribution for random numbers. |
| * |
| * The formula for the exponential probability mass function is |
| * @f$ p(x) = \lambda e^{-\lambda x} @f$. |
| * |
| * <table border=1 cellpadding=10 cellspacing=0> |
| * <caption align=top>Distribution Statistics</caption> |
| * <tr><td>Mean</td><td>@f$ \frac{1}{\lambda} @f$</td></tr> |
| * <tr><td>Median</td><td>@f$ \frac{\ln 2}{\lambda} @f$</td></tr> |
| * <tr><td>Mode</td><td>@f$ zero @f$</td></tr> |
| * <tr><td>Range</td><td>@f$[0, \infty]@f$</td></tr> |
| * <tr><td>Standard Deviation</td><td>@f$ \frac{1}{\lambda} @f$</td></tr> |
| * </table> |
| */ |
| template<typename _RealType = double> |
| class exponential_distribution |
| { |
| public: |
| // types |
| typedef _RealType input_type; |
| typedef _RealType result_type; |
| |
| public: |
| /** |
| * Constructs an exponential distribution with inverse scale parameter |
| * @f$ \lambda @f$. |
| */ |
| explicit |
| exponential_distribution(const result_type& __lambda = result_type(1)) |
| : _M_lambda(__lambda) |
| { |
| _GLIBCXX_DEBUG_ASSERT(_M_lambda > 0); |
| } |
| |
| /** |
| * Gets the inverse scale parameter of the distribution. |
| */ |
| _RealType |
| lambda() const |
| { return _M_lambda; } |
| |
| /** |
| * Resets the distribution. |
| * |
| * Has no effect on exponential distributions. |
| */ |
| void |
| reset() { } |
| |
| template<class _UniformRandomNumberGenerator> |
| result_type |
| operator()(_UniformRandomNumberGenerator& __urng) |
| { return -std::log(__urng()) / _M_lambda; } |
| |
| /** |
| * Inserts a %exponential_distribution random number distribution |
| * @p __x into the output stream @p __os. |
| * |
| * @param __os An output stream. |
| * @param __x A %exponential_distribution random number distribution. |
| * |
| * @returns The output stream with the state of @p __x inserted or in |
| * an error state. |
| */ |
| template<typename _RealType1, typename _CharT, typename _Traits> |
| friend std::basic_ostream<_CharT, _Traits>& |
| operator<<(std::basic_ostream<_CharT, _Traits>& __os, |
| const exponential_distribution<_RealType1>& __x); |
| |
| /** |
| * Extracts a %exponential_distribution random number distribution |
| * @p __x from the input stream @p __is. |
| * |
| * @param __is An input stream. |
| * @param __x A %exponential_distribution random number |
| * generator engine. |
| * |
| * @returns The input stream with @p __x extracted or in an error state. |
| */ |
| template<typename _CharT, typename _Traits> |
| friend std::basic_istream<_CharT, _Traits>& |
| operator>>(std::basic_istream<_CharT, _Traits>& __is, |
| exponential_distribution& __x) |
| { return __is >> __x._M_lambda; } |
| |
| private: |
| result_type _M_lambda; |
| }; |
| |
| |
| /** |
| * @brief A normal continuous distribution for random numbers. |
| * |
| * The formula for the normal probability mass function is |
| * @f$ p(x) = \frac{1}{\sigma \sqrt{2 \pi}} |
| * e^{- \frac{{x - mean}^ {2}}{2 \sigma ^ {2}} } @f$. |
| */ |
| template<typename _RealType = double> |
| class normal_distribution |
| { |
| public: |
| // types |
| typedef _RealType input_type; |
| typedef _RealType result_type; |
| |
| public: |
| /** |
| * Constructs a normal distribution with parameters @f$ mean @f$ and |
| * @f$ \sigma @f$. |
| */ |
| explicit |
| normal_distribution(const result_type& __mean = result_type(0), |
| const result_type& __sigma = result_type(1)) |
| : _M_mean(__mean), _M_sigma(__sigma), _M_saved_available(false) |
| { |
| _GLIBCXX_DEBUG_ASSERT(_M_sigma > 0); |
| } |
| |
| /** |
| * Gets the mean of the distribution. |
| */ |
| _RealType |
| mean() const |
| { return _M_mean; } |
| |
| /** |
| * Gets the @f$ \sigma @f$ of the distribution. |
| */ |
| _RealType |
| sigma() const |
| { return _M_sigma; } |
| |
| /** |
| * Resets the distribution. |
| */ |
| void |
| reset() |
| { _M_saved_available = false; } |
| |
| template<class _UniformRandomNumberGenerator> |
| result_type |
| operator()(_UniformRandomNumberGenerator& __urng); |
| |
| /** |
| * Inserts a %normal_distribution random number distribution |
| * @p __x into the output stream @p __os. |
| * |
| * @param __os An output stream. |
| * @param __x A %normal_distribution random number distribution. |
| * |
| * @returns The output stream with the state of @p __x inserted or in |
| * an error state. |
| */ |
| template<typename _RealType1, typename _CharT, typename _Traits> |
| friend std::basic_ostream<_CharT, _Traits>& |
| operator<<(std::basic_ostream<_CharT, _Traits>& __os, |
| const normal_distribution<_RealType1>& __x); |
| |
| /** |
| * Extracts a %normal_distribution random number distribution |
| * @p __x from the input stream @p __is. |
| * |
| * @param __is An input stream. |
| * @param __x A %normal_distribution random number generator engine. |
| * |
| * @returns The input stream with @p __x extracted or in an error state. |
| */ |
| template<typename _RealType1, typename _CharT, typename _Traits> |
| friend std::basic_istream<_CharT, _Traits>& |
| operator>>(std::basic_istream<_CharT, _Traits>& __is, |
| normal_distribution<_RealType1>& __x); |
| |
| private: |
| result_type _M_mean; |
| result_type _M_sigma; |
| result_type _M_saved; |
| bool _M_saved_available; |
| }; |
| |
| |
| /** |
| * @brief A gamma continuous distribution for random numbers. |
| * |
| * The formula for the gamma probability mass function is |
| * @f$ p(x) = \frac{1}{\Gamma(\alpha)} x^{\alpha - 1} e^{-x} @f$. |
| */ |
| template<typename _RealType = double> |
| class gamma_distribution |
| { |
| public: |
| // types |
| typedef _RealType input_type; |
| typedef _RealType result_type; |
| |
| public: |
| /** |
| * Constructs a gamma distribution with parameters @f$ \alpha @f$. |
| */ |
| explicit |
| gamma_distribution(const result_type& __alpha_val = result_type(1)) |
| : _M_alpha(__alpha_val) |
| { |
| _GLIBCXX_DEBUG_ASSERT(_M_alpha > 0); |
| _M_initialize(); |
| } |
| |
| /** |
| * Gets the @f$ \alpha @f$ of the distribution. |
| */ |
| _RealType |
| alpha() const |
| { return _M_alpha; } |
| |
| /** |
| * Resets the distribution. |
| */ |
| void |
| reset() { } |
| |
| template<class _UniformRandomNumberGenerator> |
| result_type |
| operator()(_UniformRandomNumberGenerator& __urng); |
| |
| /** |
| * Inserts a %gamma_distribution random number distribution |
| * @p __x into the output stream @p __os. |
| * |
| * @param __os An output stream. |
| * @param __x A %gamma_distribution random number distribution. |
| * |
| * @returns The output stream with the state of @p __x inserted or in |
| * an error state. |
| */ |
| template<typename _RealType1, typename _CharT, typename _Traits> |
| friend std::basic_ostream<_CharT, _Traits>& |
| operator<<(std::basic_ostream<_CharT, _Traits>& __os, |
| const gamma_distribution<_RealType1>& __x); |
| |
| /** |
| * Extracts a %gamma_distribution random number distribution |
| * @p __x from the input stream @p __is. |
| * |
| * @param __is An input stream. |
| * @param __x A %gamma_distribution random number generator engine. |
| * |
| * @returns The input stream with @p __x extracted or in an error state. |
| */ |
| template<typename _CharT, typename _Traits> |
| friend std::basic_istream<_CharT, _Traits>& |
| operator>>(std::basic_istream<_CharT, _Traits>& __is, |
| gamma_distribution& __x) |
| { |
| __is >> __x._M_alpha; |
| __x._M_initialize(); |
| return __is; |
| } |
| |
| private: |
| void |
| _M_initialize(); |
| |
| result_type _M_alpha; |
| |
| // Hosts either lambda of GB or d of modified Vaduva's. |
| result_type _M_l_d; |
| }; |
| |
| /* @} */ // group tr1_random_distributions_continuous |
| /* @} */ // group tr1_random_distributions |
| /* @} */ // group tr1_random |
| |
| _GLIBCXX_END_NAMESPACE_TR1 |
| } |
| |
| #include <tr1_impl/random.tcc> |
