Warning: This file is not a C or C++ file. It does not have highlighting.

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_CHI_SQUARED_DISTRIBUTION_H
10#define _LIBCPP___CXX03___RANDOM_CHI_SQUARED_DISTRIBUTION_H
11
12#include <__cxx03/__config>
13#include <__cxx03/__random/gamma_distribution.h>
14#include <__cxx03/__random/is_valid.h>
15#include <__cxx03/iosfwd>
16#include <__cxx03/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 <__cxx03/__undef_macros>
24
25_LIBCPP_BEGIN_NAMESPACE_STD
26
27template <class _RealType = double>
28class _LIBCPP_TEMPLATE_VIS chi_squared_distribution {
29 static_assert(__libcpp_random_is_valid_realtype<_RealType>::value,
30 "RealType must be a supported floating-point type");
31
32public:
33 // types
34 typedef _RealType result_type;
35
36 class _LIBCPP_TEMPLATE_VIS param_type {
37 result_type __n_;
38
39 public:
40 typedef chi_squared_distribution distribution_type;
41
42 _LIBCPP_HIDE_FROM_ABI explicit param_type(result_type __n = 1) : __n_(__n) {}
43
44 _LIBCPP_HIDE_FROM_ABI result_type n() const { return __n_; }
45
46 friend _LIBCPP_HIDE_FROM_ABI bool operator==(const param_type& __x, const param_type& __y) {
47 return __x.__n_ == __y.__n_;
48 }
49 friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const param_type& __x, const param_type& __y) { return !(__x == __y); }
50 };
51
52private:
53 param_type __p_;
54
55public:
56 // constructor and reset functions
57 _LIBCPP_HIDE_FROM_ABI explicit chi_squared_distribution(result_type __n = 1) : __p_(param_type(__n)) {}
58 _LIBCPP_HIDE_FROM_ABI explicit chi_squared_distribution(const param_type& __p) : __p_(__p) {}
59 _LIBCPP_HIDE_FROM_ABI void reset() {}
60
61 // generating functions
62 template <class _URNG>
63 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g) {
64 return (*this)(__g, __p_);
65 }
66 template <class _URNG>
67 _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g, const param_type& __p) {
68 return gamma_distribution<result_type>(__p.n() / 2, 2)(__g);
69 }
70
71 // property functions
72 _LIBCPP_HIDE_FROM_ABI result_type n() const { return __p_.n(); }
73
74 _LIBCPP_HIDE_FROM_ABI param_type param() const { return __p_; }
75 _LIBCPP_HIDE_FROM_ABI void param(const param_type& __p) { __p_ = __p; }
76
77 _LIBCPP_HIDE_FROM_ABI result_type min() const { return 0; }
78 _LIBCPP_HIDE_FROM_ABI result_type max() const { return numeric_limits<result_type>::infinity(); }
79
80 friend _LIBCPP_HIDE_FROM_ABI bool
81 operator==(const chi_squared_distribution& __x, const chi_squared_distribution& __y) {
82 return __x.__p_ == __y.__p_;
83 }
84 friend _LIBCPP_HIDE_FROM_ABI bool
85 operator!=(const chi_squared_distribution& __x, const chi_squared_distribution& __y) {
86 return !(__x == __y);
87 }
88};
89
90template <class _CharT, class _Traits, class _RT>
91_LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>&
92operator<<(basic_ostream<_CharT, _Traits>& __os, const chi_squared_distribution<_RT>& __x) {
93 __save_flags<_CharT, _Traits> __lx(__os);
94 typedef basic_ostream<_CharT, _Traits> _OStream;
95 __os.flags(_OStream::dec | _OStream::left | _OStream::fixed | _OStream::scientific);
96 __os << __x.n();
97 return __os;
98}
99
100template <class _CharT, class _Traits, class _RT>
101_LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>&
102operator>>(basic_istream<_CharT, _Traits>& __is, chi_squared_distribution<_RT>& __x) {
103 typedef chi_squared_distribution<_RT> _Eng;
104 typedef typename _Eng::result_type result_type;
105 typedef typename _Eng::param_type param_type;
106 __save_flags<_CharT, _Traits> __lx(__is);
107 typedef basic_istream<_CharT, _Traits> _Istream;
108 __is.flags(_Istream::dec | _Istream::skipws);
109 result_type __n;
110 __is >> __n;
111 if (!__is.fail())
112 __x.param(param_type(__n));
113 return __is;
114}
115
116_LIBCPP_END_NAMESPACE_STD
117
118_LIBCPP_POP_MACROS
119
120#endif // _LIBCPP___CXX03___RANDOM_CHI_SQUARED_DISTRIBUTION_H
121

Warning: This file is not a C or C++ file. It does not have highlighting.

source code of libcxx/include/__cxx03/__random/chi_squared_distribution.h