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
28template <class _RealType = double>
29class lognormal_distribution {
30 static_assert(__libcpp_random_is_valid_realtype<_RealType>::value,
31 "RealType must be a supported floating-point type");
32
33public:
34 // types
35 typedef _RealType result_type;
36
37 class param_type {
38 result_type __m_;
39 result_type __s_;
40
41 public:
42 typedef lognormal_distribution distribution_type;
43
44 _LIBCPP_HIDE_FROM_ABI explicit param_type(result_type __m = 0, result_type __s = 1) : __m_(__m), __s_(__s) {}
45
46 _LIBCPP_HIDE_FROM_ABI result_type m() const { return __m_; }
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
55private:
56 normal_distribution<result_type> __nd_;
57
58public:
59 // constructor and reset functions
60#ifndef _LIBCPP_CXX03_LANG
61 _LIBCPP_HIDE_FROM_ABI lognormal_distribution() : lognormal_distribution(0) {}
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
66 _LIBCPP_HIDE_FROM_ABI explicit lognormal_distribution(const param_type& __p) : __nd_(__p.m(), __p.s()) {}
67 _LIBCPP_HIDE_FROM_ABI void reset() { __nd_.reset(); }
68
69 // generating functions
70 template <class _URNG>
71 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g) {
72 return std::exp(__nd_(__g));
73 }
74
75 template <class _URNG>
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
82 _LIBCPP_HIDE_FROM_ABI result_type m() const { return __nd_.mean(); }
83 _LIBCPP_HIDE_FROM_ABI result_type s() const { return __nd_.stddev(); }
84
85 _LIBCPP_HIDE_FROM_ABI param_type param() const { return param_type(__nd_.mean(), __nd_.stddev()); }
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
91 _LIBCPP_HIDE_FROM_ABI result_type min() const { return 0; }
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
110template <class _CharT, class _Traits, class _RT>
111inline _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>&
112operator<<(basic_ostream<_CharT, _Traits>& __os, const lognormal_distribution<_RT>& __x) {
113 return __os << __x.__nd_;
114}
115
116template <class _CharT, class _Traits, class _RT>
117inline _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&
118operator>>(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