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___RANDOM_WEIBULL_DISTRIBUTION_H 10 #define _LIBCPP___RANDOM_WEIBULL_DISTRIBUTION_H 11 12 #include <__config> 13 #include <__random/exponential_distribution.h> 14 #include <cmath> 15 #include <iosfwd> 16 #include <limits> 17 18 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 19 # pragma GCC system_header 20 #endif 21 22 _LIBCPP_PUSH_MACROS 23 #include <__undef_macros> 24 25 _LIBCPP_BEGIN_NAMESPACE_STD 26 27 template<class _RealType = double> 28 class _LIBCPP_TEMPLATE_VIS weibull_distribution 29 { 30 public: 31 // types 32 typedef _RealType result_type; 33 34 class _LIBCPP_TEMPLATE_VIS param_type 35 { 36 result_type __a_; 37 result_type __b_; 38 public: 39 typedef weibull_distribution distribution_type; 40 41 _LIBCPP_INLINE_VISIBILITY 42 explicit param_type(result_type __a = 1, result_type __b = 1) 43 : __a_(__a), __b_(__b) {} 44 45 _LIBCPP_INLINE_VISIBILITY 46 result_type a() const {return __a_;} 47 _LIBCPP_INLINE_VISIBILITY 48 result_type b() const {return __b_;} 49 50 friend _LIBCPP_INLINE_VISIBILITY 51 bool operator==(const param_type& __x, const param_type& __y) 52 {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;} 53 friend _LIBCPP_INLINE_VISIBILITY 54 bool operator!=(const param_type& __x, const param_type& __y) 55 {return !(__x == __y);} 56 }; 57 58 private: 59 param_type __p_; 60 61 public: 62 // constructor and reset functions 63 #ifndef _LIBCPP_CXX03_LANG 64 _LIBCPP_INLINE_VISIBILITY 65 weibull_distribution() : weibull_distribution(1) {} 66 _LIBCPP_INLINE_VISIBILITY 67 explicit weibull_distribution(result_type __a, result_type __b = 1) 68 : __p_(param_type(__a, __b)) {} 69 #else 70 _LIBCPP_INLINE_VISIBILITY 71 explicit weibull_distribution(result_type __a = 1, result_type __b = 1) 72 : __p_(param_type(__a, __b)) {} 73 #endif 74 _LIBCPP_INLINE_VISIBILITY 75 explicit weibull_distribution(const param_type& __p) 76 : __p_(__p) {} 77 _LIBCPP_INLINE_VISIBILITY 78 void reset() {} 79 80 // generating functions 81 template<class _URNG> 82 _LIBCPP_INLINE_VISIBILITY 83 result_type operator()(_URNG& __g) 84 {return (*this)(__g, __p_);} 85 template<class _URNG> 86 _LIBCPP_INLINE_VISIBILITY 87 result_type operator()(_URNG& __g, const param_type& __p) 88 {return __p.b() * 89 _VSTD::pow(exponential_distribution<result_type>()(__g), 1/__p.a());} 90 91 // property functions 92 _LIBCPP_INLINE_VISIBILITY 93 result_type a() const {return __p_.a();} 94 _LIBCPP_INLINE_VISIBILITY 95 result_type b() const {return __p_.b();} 96 97 _LIBCPP_INLINE_VISIBILITY 98 param_type param() const {return __p_;} 99 _LIBCPP_INLINE_VISIBILITY 100 void param(const param_type& __p) {__p_ = __p;} 101 102 _LIBCPP_INLINE_VISIBILITY 103 result_type min() const {return 0;} 104 _LIBCPP_INLINE_VISIBILITY 105 result_type max() const {return numeric_limits<result_type>::infinity();} 106 107 friend _LIBCPP_INLINE_VISIBILITY 108 bool operator==(const weibull_distribution& __x, 109 const weibull_distribution& __y) 110 {return __x.__p_ == __y.__p_;} 111 friend _LIBCPP_INLINE_VISIBILITY 112 bool operator!=(const weibull_distribution& __x, 113 const weibull_distribution& __y) 114 {return !(__x == __y);} 115 }; 116 117 template <class _CharT, class _Traits, class _RT> 118 basic_ostream<_CharT, _Traits>& 119 operator<<(basic_ostream<_CharT, _Traits>& __os, 120 const weibull_distribution<_RT>& __x) 121 { 122 __save_flags<_CharT, _Traits> __lx(__os); 123 typedef basic_ostream<_CharT, _Traits> _OStream; 124 __os.flags(_OStream::dec | _OStream::left | _OStream::fixed | 125 _OStream::scientific); 126 _CharT __sp = __os.widen(' '); 127 __os.fill(__sp); 128 __os << __x.a() << __sp << __x.b(); 129 return __os; 130 } 131 132 template <class _CharT, class _Traits, class _RT> 133 basic_istream<_CharT, _Traits>& 134 operator>>(basic_istream<_CharT, _Traits>& __is, 135 weibull_distribution<_RT>& __x) 136 { 137 typedef weibull_distribution<_RT> _Eng; 138 typedef typename _Eng::result_type result_type; 139 typedef typename _Eng::param_type param_type; 140 __save_flags<_CharT, _Traits> __lx(__is); 141 typedef basic_istream<_CharT, _Traits> _Istream; 142 __is.flags(_Istream::dec | _Istream::skipws); 143 result_type __a; 144 result_type __b; 145 __is >> __a >> __b; 146 if (!__is.fail()) 147 __x.param(param_type(__a, __b)); 148 return __is; 149 } 150 151 _LIBCPP_END_NAMESPACE_STD 152 153 _LIBCPP_POP_MACROS 154 155 #endif // _LIBCPP___RANDOM_WEIBULL_DISTRIBUTION_H 156