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_LOGNORMAL_DISTRIBUTION_H 10 #define _LIBCPP___CXX03___RANDOM_LOGNORMAL_DISTRIBUTION_H 11 12 #include <__cxx03/__config> 13 #include <__cxx03/__random/is_valid.h> 14 #include <__cxx03/__random/normal_distribution.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 lognormal_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 __m_; 39 result_type __s_; 40 41 public: 42 typedef lognormal_distribution distribution_type; 43 __m_(__m)44 _LIBCPP_HIDE_FROM_ABI explicit param_type(result_type __m = 0, result_type __s = 1) : __m_(__m), __s_(__s) {} 45 m()46 _LIBCPP_HIDE_FROM_ABI result_type m() const { return __m_; } s()47 _LIBCPP_HIDE_FROM_ABI result_type s() const { return __s_; } 48 49 friend _LIBCPP_HIDE_FROM_ABI bool operator==(const param_type& __x, const param_type& __y) { 50 return __x.__m_ == __y.__m_ && __x.__s_ == __y.__s_; 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 normal_distribution<result_type> __nd_; 57 58 public: 59 // constructor and reset functions __nd_(__m,__s)60 _LIBCPP_HIDE_FROM_ABI explicit lognormal_distribution(result_type __m = 0, result_type __s = 1) : __nd_(__m, __s) {} lognormal_distribution(const param_type & __p)61 _LIBCPP_HIDE_FROM_ABI explicit lognormal_distribution(const param_type& __p) : __nd_(__p.m(), __p.s()) {} reset()62 _LIBCPP_HIDE_FROM_ABI void reset() { __nd_.reset(); } 63 64 // generating functions 65 template <class _URNG> operator()66 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g) { 67 return std::exp(__nd_(__g)); 68 } 69 70 template <class _URNG> operator()71 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g, const param_type& __p) { 72 typename normal_distribution<result_type>::param_type __pn(__p.m(), __p.s()); 73 return std::exp(__nd_(__g, __pn)); 74 } 75 76 // property functions m()77 _LIBCPP_HIDE_FROM_ABI result_type m() const { return __nd_.mean(); } s()78 _LIBCPP_HIDE_FROM_ABI result_type s() const { return __nd_.stddev(); } 79 param()80 _LIBCPP_HIDE_FROM_ABI param_type param() const { return param_type(__nd_.mean(), __nd_.stddev()); } param(const param_type & __p)81 _LIBCPP_HIDE_FROM_ABI void param(const param_type& __p) { 82 typename normal_distribution<result_type>::param_type __pn(__p.m(), __p.s()); 83 __nd_.param(__pn); 84 } 85 min()86 _LIBCPP_HIDE_FROM_ABI result_type min() const { return 0; } max()87 _LIBCPP_HIDE_FROM_ABI result_type max() const { return numeric_limits<result_type>::infinity(); } 88 89 friend _LIBCPP_HIDE_FROM_ABI bool operator==(const lognormal_distribution& __x, const lognormal_distribution& __y) { 90 return __x.__nd_ == __y.__nd_; 91 } 92 friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const lognormal_distribution& __x, const lognormal_distribution& __y) { 93 return !(__x == __y); 94 } 95 96 template <class _CharT, class _Traits, class _RT> 97 friend basic_ostream<_CharT, _Traits>& 98 operator<<(basic_ostream<_CharT, _Traits>& __os, const lognormal_distribution<_RT>& __x); 99 100 template <class _CharT, class _Traits, class _RT> 101 friend basic_istream<_CharT, _Traits>& 102 operator>>(basic_istream<_CharT, _Traits>& __is, lognormal_distribution<_RT>& __x); 103 }; 104 105 template <class _CharT, class _Traits, class _RT> 106 inline _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>& 107 operator<<(basic_ostream<_CharT, _Traits>& __os, const lognormal_distribution<_RT>& __x) { 108 return __os << __x.__nd_; 109 } 110 111 template <class _CharT, class _Traits, class _RT> 112 inline _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>& 113 operator>>(basic_istream<_CharT, _Traits>& __is, lognormal_distribution<_RT>& __x) { 114 return __is >> __x.__nd_; 115 } 116 117 _LIBCPP_END_NAMESPACE_STD 118 119 _LIBCPP_POP_MACROS 120 121 #endif // _LIBCPP___CXX03___RANDOM_LOGNORMAL_DISTRIBUTION_H 122