1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef _LIBCPP___CXX03___RANDOM_WEIBULL_DISTRIBUTION_H 10 #define _LIBCPP___CXX03___RANDOM_WEIBULL_DISTRIBUTION_H 11 12 #include <__cxx03/__config> 13 #include <__cxx03/__random/exponential_distribution.h> 14 #include <__cxx03/__random/is_valid.h> 15 #include <__cxx03/cmath> 16 #include <__cxx03/iosfwd> 17 #include <__cxx03/limits> 18 19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 20 # pragma GCC system_header 21 #endif 22 23 _LIBCPP_PUSH_MACROS 24 #include <__cxx03/__undef_macros> 25 26 _LIBCPP_BEGIN_NAMESPACE_STD 27 28 template <class _RealType = double> 29 class _LIBCPP_TEMPLATE_VIS weibull_distribution { 30 static_assert(__libcpp_random_is_valid_realtype<_RealType>::value, 31 "RealType must be a supported floating-point type"); 32 33 public: 34 // types 35 typedef _RealType result_type; 36 37 class _LIBCPP_TEMPLATE_VIS param_type { 38 result_type __a_; 39 result_type __b_; 40 41 public: 42 typedef weibull_distribution distribution_type; 43 __a_(__a)44 _LIBCPP_HIDE_FROM_ABI explicit param_type(result_type __a = 1, result_type __b = 1) : __a_(__a), __b_(__b) {} 45 a()46 _LIBCPP_HIDE_FROM_ABI result_type a() const { return __a_; } b()47 _LIBCPP_HIDE_FROM_ABI result_type b() const { return __b_; } 48 49 friend _LIBCPP_HIDE_FROM_ABI bool operator==(const param_type& __x, const param_type& __y) { 50 return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_; 51 } 52 friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const param_type& __x, const param_type& __y) { return !(__x == __y); } 53 }; 54 55 private: 56 param_type __p_; 57 58 public: 59 // constructor and reset functions 60 _LIBCPP_HIDE_FROM_ABI explicit weibull_distribution(result_type __a = 1, result_type __b = 1) __p_(param_type (__a,__b))61 : __p_(param_type(__a, __b)) {} weibull_distribution(const param_type & __p)62 _LIBCPP_HIDE_FROM_ABI explicit weibull_distribution(const param_type& __p) : __p_(__p) {} reset()63 _LIBCPP_HIDE_FROM_ABI void reset() {} 64 65 // generating functions 66 template <class _URNG> operator()67 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g) { 68 return (*this)(__g, __p_); 69 } 70 template <class _URNG> operator()71 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g, const param_type& __p) { 72 return __p.b() * std::pow(exponential_distribution<result_type>()(__g), 1 / __p.a()); 73 } 74 75 // property functions a()76 _LIBCPP_HIDE_FROM_ABI result_type a() const { return __p_.a(); } b()77 _LIBCPP_HIDE_FROM_ABI result_type b() const { return __p_.b(); } 78 param()79 _LIBCPP_HIDE_FROM_ABI param_type param() const { return __p_; } param(const param_type & __p)80 _LIBCPP_HIDE_FROM_ABI void param(const param_type& __p) { __p_ = __p; } 81 min()82 _LIBCPP_HIDE_FROM_ABI result_type min() const { return 0; } max()83 _LIBCPP_HIDE_FROM_ABI result_type max() const { return numeric_limits<result_type>::infinity(); } 84 85 friend _LIBCPP_HIDE_FROM_ABI bool operator==(const weibull_distribution& __x, const weibull_distribution& __y) { 86 return __x.__p_ == __y.__p_; 87 } 88 friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const weibull_distribution& __x, const weibull_distribution& __y) { 89 return !(__x == __y); 90 } 91 }; 92 93 template <class _CharT, class _Traits, class _RT> 94 _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>& 95 operator<<(basic_ostream<_CharT, _Traits>& __os, const weibull_distribution<_RT>& __x) { 96 __save_flags<_CharT, _Traits> __lx(__os); 97 typedef basic_ostream<_CharT, _Traits> _OStream; 98 __os.flags(_OStream::dec | _OStream::left | _OStream::fixed | _OStream::scientific); 99 _CharT __sp = __os.widen(' '); 100 __os.fill(__sp); 101 __os << __x.a() << __sp << __x.b(); 102 return __os; 103 } 104 105 template <class _CharT, class _Traits, class _RT> 106 _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>& 107 operator>>(basic_istream<_CharT, _Traits>& __is, weibull_distribution<_RT>& __x) { 108 typedef weibull_distribution<_RT> _Eng; 109 typedef typename _Eng::result_type result_type; 110 typedef typename _Eng::param_type param_type; 111 __save_flags<_CharT, _Traits> __lx(__is); 112 typedef basic_istream<_CharT, _Traits> _Istream; 113 __is.flags(_Istream::dec | _Istream::skipws); 114 result_type __a; 115 result_type __b; 116 __is >> __a >> __b; 117 if (!__is.fail()) 118 __x.param(param_type(__a, __b)); 119 return __is; 120 } 121 122 _LIBCPP_END_NAMESPACE_STD 123 124 _LIBCPP_POP_MACROS 125 126 #endif // _LIBCPP___CXX03___RANDOM_WEIBULL_DISTRIBUTION_H 127