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 <__random/is_valid.h> 15 #include <cmath> 16 #include <iosfwd> 17 #include <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 <__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 44 _LIBCPP_HIDE_FROM_ABI explicit param_type(result_type __a = 1, result_type __b = 1) : __a_(__a), __b_(__b) {} 45 46 _LIBCPP_HIDE_FROM_ABI result_type a() const { return __a_; } 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 #ifndef _LIBCPP_CXX03_LANG 61 _LIBCPP_HIDE_FROM_ABI weibull_distribution() : weibull_distribution(1) {} 62 _LIBCPP_HIDE_FROM_ABI explicit weibull_distribution(result_type __a, result_type __b = 1) 63 : __p_(param_type(__a, __b)) {} 64 #else 65 _LIBCPP_HIDE_FROM_ABI explicit weibull_distribution(result_type __a = 1, result_type __b = 1) 66 : __p_(param_type(__a, __b)) {} 67 #endif 68 _LIBCPP_HIDE_FROM_ABI explicit weibull_distribution(const param_type& __p) : __p_(__p) {} 69 _LIBCPP_HIDE_FROM_ABI void reset() {} 70 71 // generating functions 72 template <class _URNG> 73 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g) { 74 return (*this)(__g, __p_); 75 } 76 template <class _URNG> 77 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g, const param_type& __p) { 78 return __p.b() * std::pow(exponential_distribution<result_type>()(__g), 1 / __p.a()); 79 } 80 81 // property functions 82 _LIBCPP_HIDE_FROM_ABI result_type a() const { return __p_.a(); } 83 _LIBCPP_HIDE_FROM_ABI result_type b() const { return __p_.b(); } 84 85 _LIBCPP_HIDE_FROM_ABI param_type param() const { return __p_; } 86 _LIBCPP_HIDE_FROM_ABI void param(const param_type& __p) { __p_ = __p; } 87 88 _LIBCPP_HIDE_FROM_ABI result_type min() const { return 0; } 89 _LIBCPP_HIDE_FROM_ABI result_type max() const { return numeric_limits<result_type>::infinity(); } 90 91 friend _LIBCPP_HIDE_FROM_ABI bool operator==(const weibull_distribution& __x, const weibull_distribution& __y) { 92 return __x.__p_ == __y.__p_; 93 } 94 friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const weibull_distribution& __x, const weibull_distribution& __y) { 95 return !(__x == __y); 96 } 97 }; 98 99 template <class _CharT, class _Traits, class _RT> 100 _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>& 101 operator<<(basic_ostream<_CharT, _Traits>& __os, const weibull_distribution<_RT>& __x) { 102 __save_flags<_CharT, _Traits> __lx(__os); 103 typedef basic_ostream<_CharT, _Traits> _OStream; 104 __os.flags(_OStream::dec | _OStream::left | _OStream::fixed | _OStream::scientific); 105 _CharT __sp = __os.widen(' '); 106 __os.fill(__sp); 107 __os << __x.a() << __sp << __x.b(); 108 return __os; 109 } 110 111 template <class _CharT, class _Traits, class _RT> 112 _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>& 113 operator>>(basic_istream<_CharT, _Traits>& __is, weibull_distribution<_RT>& __x) { 114 typedef weibull_distribution<_RT> _Eng; 115 typedef typename _Eng::result_type result_type; 116 typedef typename _Eng::param_type param_type; 117 __save_flags<_CharT, _Traits> __lx(__is); 118 typedef basic_istream<_CharT, _Traits> _Istream; 119 __is.flags(_Istream::dec | _Istream::skipws); 120 result_type __a; 121 result_type __b; 122 __is >> __a >> __b; 123 if (!__is.fail()) 124 __x.param(param_type(__a, __b)); 125 return __is; 126 } 127 128 _LIBCPP_END_NAMESPACE_STD 129 130 _LIBCPP_POP_MACROS 131 132 #endif // _LIBCPP___RANDOM_WEIBULL_DISTRIBUTION_H 133