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_LOGNORMAL_DISTRIBUTION_H 10 #define _LIBCPP___RANDOM_LOGNORMAL_DISTRIBUTION_H 11 12 #include <__config> 13 #include <__random/is_valid.h> 14 #include <__random/normal_distribution.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 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 60 #ifndef _LIBCPP_CXX03_LANG lognormal_distribution()61 _LIBCPP_HIDE_FROM_ABI lognormal_distribution() : lognormal_distribution(0) {} __nd_(__m,__s)62 _LIBCPP_HIDE_FROM_ABI explicit lognormal_distribution(result_type __m, result_type __s = 1) : __nd_(__m, __s) {} 63 #else 64 _LIBCPP_HIDE_FROM_ABI explicit lognormal_distribution(result_type __m = 0, result_type __s = 1) : __nd_(__m, __s) {} 65 #endif lognormal_distribution(const param_type & __p)66 _LIBCPP_HIDE_FROM_ABI explicit lognormal_distribution(const param_type& __p) : __nd_(__p.m(), __p.s()) {} reset()67 _LIBCPP_HIDE_FROM_ABI void reset() { __nd_.reset(); } 68 69 // generating functions 70 template <class _URNG> operator()71 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g) { 72 return std::exp(__nd_(__g)); 73 } 74 75 template <class _URNG> operator()76 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g, const param_type& __p) { 77 typename normal_distribution<result_type>::param_type __pn(__p.m(), __p.s()); 78 return std::exp(__nd_(__g, __pn)); 79 } 80 81 // property functions m()82 _LIBCPP_HIDE_FROM_ABI result_type m() const { return __nd_.mean(); } s()83 _LIBCPP_HIDE_FROM_ABI result_type s() const { return __nd_.stddev(); } 84 param()85 _LIBCPP_HIDE_FROM_ABI param_type param() const { return param_type(__nd_.mean(), __nd_.stddev()); } param(const param_type & __p)86 _LIBCPP_HIDE_FROM_ABI void param(const param_type& __p) { 87 typename normal_distribution<result_type>::param_type __pn(__p.m(), __p.s()); 88 __nd_.param(__pn); 89 } 90 min()91 _LIBCPP_HIDE_FROM_ABI result_type min() const { return 0; } max()92 _LIBCPP_HIDE_FROM_ABI result_type max() const { return numeric_limits<result_type>::infinity(); } 93 94 friend _LIBCPP_HIDE_FROM_ABI bool operator==(const lognormal_distribution& __x, const lognormal_distribution& __y) { 95 return __x.__nd_ == __y.__nd_; 96 } 97 friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const lognormal_distribution& __x, const lognormal_distribution& __y) { 98 return !(__x == __y); 99 } 100 101 template <class _CharT, class _Traits, class _RT> 102 friend basic_ostream<_CharT, _Traits>& 103 operator<<(basic_ostream<_CharT, _Traits>& __os, const lognormal_distribution<_RT>& __x); 104 105 template <class _CharT, class _Traits, class _RT> 106 friend basic_istream<_CharT, _Traits>& 107 operator>>(basic_istream<_CharT, _Traits>& __is, lognormal_distribution<_RT>& __x); 108 }; 109 110 template <class _CharT, class _Traits, class _RT> 111 inline _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>& 112 operator<<(basic_ostream<_CharT, _Traits>& __os, const lognormal_distribution<_RT>& __x) { 113 return __os << __x.__nd_; 114 } 115 116 template <class _CharT, class _Traits, class _RT> 117 inline _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>& 118 operator>>(basic_istream<_CharT, _Traits>& __is, lognormal_distribution<_RT>& __x) { 119 return __is >> __x.__nd_; 120 } 121 122 _LIBCPP_END_NAMESPACE_STD 123 124 _LIBCPP_POP_MACROS 125 126 #endif // _LIBCPP___RANDOM_LOGNORMAL_DISTRIBUTION_H 127