| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef _LIBCPP___RANDOM_CAUCHY_DISTRIBUTION_H |
| #define _LIBCPP___RANDOM_CAUCHY_DISTRIBUTION_H |
| |
| #include <__config> |
| #include <__random/is_valid.h> |
| #include <__random/uniform_real_distribution.h> |
| #include <cmath> |
| #include <iosfwd> |
| #include <limits> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| # pragma GCC system_header |
| #endif |
| |
| _LIBCPP_PUSH_MACROS |
| #include <__undef_macros> |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| template <class _RealType = double> |
| class _LIBCPP_TEMPLATE_VIS cauchy_distribution { |
| static_assert(__libcpp_random_is_valid_realtype<_RealType>::value, |
| "RealType must be a supported floating-point type"); |
| |
| public: |
| // types |
| typedef _RealType result_type; |
| |
| class _LIBCPP_TEMPLATE_VIS param_type { |
| result_type __a_; |
| result_type __b_; |
| |
| public: |
| typedef cauchy_distribution distribution_type; |
| |
| _LIBCPP_HIDE_FROM_ABI explicit param_type(result_type __a = 0, result_type __b = 1) : __a_(__a), __b_(__b) {} |
| |
| _LIBCPP_HIDE_FROM_ABI result_type a() const { return __a_; } |
| _LIBCPP_HIDE_FROM_ABI result_type b() const { return __b_; } |
| |
| friend _LIBCPP_HIDE_FROM_ABI bool operator==(const param_type& __x, const param_type& __y) { |
| return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_; |
| } |
| friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const param_type& __x, const param_type& __y) { return !(__x == __y); } |
| }; |
| |
| private: |
| param_type __p_; |
| |
| public: |
| // constructor and reset functions |
| #ifndef _LIBCPP_CXX03_LANG |
| _LIBCPP_HIDE_FROM_ABI cauchy_distribution() : cauchy_distribution(0) {} |
| _LIBCPP_HIDE_FROM_ABI explicit cauchy_distribution(result_type __a, result_type __b = 1) |
| : __p_(param_type(__a, __b)) {} |
| #else |
| _LIBCPP_HIDE_FROM_ABI explicit cauchy_distribution(result_type __a = 0, result_type __b = 1) |
| : __p_(param_type(__a, __b)) {} |
| #endif |
| _LIBCPP_HIDE_FROM_ABI explicit cauchy_distribution(const param_type& __p) : __p_(__p) {} |
| _LIBCPP_HIDE_FROM_ABI void reset() {} |
| |
| // generating functions |
| template <class _URNG> |
| _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g) { |
| return (*this)(__g, __p_); |
| } |
| template <class _URNG> |
| _LIBCPP_HIDE_FROM_ABI result_type operator()(_URNG& __g, const param_type& __p); |
| |
| // property functions |
| _LIBCPP_HIDE_FROM_ABI result_type a() const { return __p_.a(); } |
| _LIBCPP_HIDE_FROM_ABI result_type b() const { return __p_.b(); } |
| |
| _LIBCPP_HIDE_FROM_ABI param_type param() const { return __p_; } |
| _LIBCPP_HIDE_FROM_ABI void param(const param_type& __p) { __p_ = __p; } |
| |
| _LIBCPP_HIDE_FROM_ABI result_type min() const { return -numeric_limits<result_type>::infinity(); } |
| _LIBCPP_HIDE_FROM_ABI result_type max() const { return numeric_limits<result_type>::infinity(); } |
| |
| friend _LIBCPP_HIDE_FROM_ABI bool operator==(const cauchy_distribution& __x, const cauchy_distribution& __y) { |
| return __x.__p_ == __y.__p_; |
| } |
| friend _LIBCPP_HIDE_FROM_ABI bool operator!=(const cauchy_distribution& __x, const cauchy_distribution& __y) { |
| return !(__x == __y); |
| } |
| }; |
| |
| template <class _RealType> |
| template <class _URNG> |
| inline _RealType cauchy_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p) { |
| static_assert(__libcpp_random_is_valid_urng<_URNG>::value, ""); |
| uniform_real_distribution<result_type> __gen; |
| // purposefully let tan arg get as close to pi/2 as it wants, tan will return a finite |
| return __p.a() + __p.b() * std::tan(3.1415926535897932384626433832795 * __gen(__g)); |
| } |
| |
| template <class _CharT, class _Traits, class _RT> |
| _LIBCPP_HIDE_FROM_ABI basic_ostream<_CharT, _Traits>& |
| operator<<(basic_ostream<_CharT, _Traits>& __os, const cauchy_distribution<_RT>& __x) { |
| __save_flags<_CharT, _Traits> __lx(__os); |
| typedef basic_ostream<_CharT, _Traits> _OStream; |
| __os.flags(_OStream::dec | _OStream::left | _OStream::fixed | _OStream::scientific); |
| _CharT __sp = __os.widen(' '); |
| __os.fill(__sp); |
| __os << __x.a() << __sp << __x.b(); |
| return __os; |
| } |
| |
| template <class _CharT, class _Traits, class _RT> |
| _LIBCPP_HIDE_FROM_ABI basic_istream<_CharT, _Traits>& |
| operator>>(basic_istream<_CharT, _Traits>& __is, cauchy_distribution<_RT>& __x) { |
| typedef cauchy_distribution<_RT> _Eng; |
| typedef typename _Eng::result_type result_type; |
| typedef typename _Eng::param_type param_type; |
| __save_flags<_CharT, _Traits> __lx(__is); |
| typedef basic_istream<_CharT, _Traits> _Istream; |
| __is.flags(_Istream::dec | _Istream::skipws); |
| result_type __a; |
| result_type __b; |
| __is >> __a >> __b; |
| if (!__is.fail()) |
| __x.param(param_type(__a, __b)); |
| return __is; |
| } |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| _LIBCPP_POP_MACROS |
| |
| #endif // _LIBCPP___RANDOM_CAUCHY_DISTRIBUTION_H |