357 lines
12 KiB
C++
357 lines
12 KiB
C++
//===----------------------------------------------------------------------===//
|
|
//
|
|
// 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_PIECEWISE_CONSTANT_DISTRIBUTION_H
|
|
#define _LIBCPP___RANDOM_PIECEWISE_CONSTANT_DISTRIBUTION_H
|
|
|
|
#include <__algorithm/upper_bound.h>
|
|
#include <__config>
|
|
#include <__random/uniform_real_distribution.h>
|
|
#include <iosfwd>
|
|
#include <numeric>
|
|
#include <vector>
|
|
|
|
#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 piecewise_constant_distribution
|
|
{
|
|
public:
|
|
// types
|
|
typedef _RealType result_type;
|
|
|
|
class _LIBCPP_TEMPLATE_VIS param_type
|
|
{
|
|
vector<result_type> __b_;
|
|
vector<result_type> __densities_;
|
|
vector<result_type> __areas_;
|
|
public:
|
|
typedef piecewise_constant_distribution distribution_type;
|
|
|
|
param_type();
|
|
template<class _InputIteratorB, class _InputIteratorW>
|
|
param_type(_InputIteratorB __fB, _InputIteratorB __lB,
|
|
_InputIteratorW __fW);
|
|
#ifndef _LIBCPP_CXX03_LANG
|
|
template<class _UnaryOperation>
|
|
param_type(initializer_list<result_type> __bl, _UnaryOperation __fw);
|
|
#endif // _LIBCPP_CXX03_LANG
|
|
template<class _UnaryOperation>
|
|
param_type(size_t __nw, result_type __xmin, result_type __xmax,
|
|
_UnaryOperation __fw);
|
|
param_type(param_type const&) = default;
|
|
param_type & operator=(const param_type& __rhs);
|
|
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
vector<result_type> intervals() const {return __b_;}
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
vector<result_type> densities() const {return __densities_;}
|
|
|
|
friend _LIBCPP_INLINE_VISIBILITY
|
|
bool operator==(const param_type& __x, const param_type& __y)
|
|
{return __x.__densities_ == __y.__densities_ && __x.__b_ == __y.__b_;}
|
|
friend _LIBCPP_INLINE_VISIBILITY
|
|
bool operator!=(const param_type& __x, const param_type& __y)
|
|
{return !(__x == __y);}
|
|
|
|
private:
|
|
void __init();
|
|
|
|
friend class piecewise_constant_distribution;
|
|
|
|
template <class _CharT, class _Traits, class _RT>
|
|
friend
|
|
basic_ostream<_CharT, _Traits>&
|
|
operator<<(basic_ostream<_CharT, _Traits>& __os,
|
|
const piecewise_constant_distribution<_RT>& __x);
|
|
|
|
template <class _CharT, class _Traits, class _RT>
|
|
friend
|
|
basic_istream<_CharT, _Traits>&
|
|
operator>>(basic_istream<_CharT, _Traits>& __is,
|
|
piecewise_constant_distribution<_RT>& __x);
|
|
};
|
|
|
|
private:
|
|
param_type __p_;
|
|
|
|
public:
|
|
// constructor and reset functions
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
piecewise_constant_distribution() {}
|
|
template<class _InputIteratorB, class _InputIteratorW>
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
piecewise_constant_distribution(_InputIteratorB __fB,
|
|
_InputIteratorB __lB,
|
|
_InputIteratorW __fW)
|
|
: __p_(__fB, __lB, __fW) {}
|
|
|
|
#ifndef _LIBCPP_CXX03_LANG
|
|
template<class _UnaryOperation>
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
piecewise_constant_distribution(initializer_list<result_type> __bl,
|
|
_UnaryOperation __fw)
|
|
: __p_(__bl, __fw) {}
|
|
#endif // _LIBCPP_CXX03_LANG
|
|
|
|
template<class _UnaryOperation>
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
piecewise_constant_distribution(size_t __nw, result_type __xmin,
|
|
result_type __xmax, _UnaryOperation __fw)
|
|
: __p_(__nw, __xmin, __xmax, __fw) {}
|
|
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
explicit piecewise_constant_distribution(const param_type& __p)
|
|
: __p_(__p) {}
|
|
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
void reset() {}
|
|
|
|
// generating functions
|
|
template<class _URNG>
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
result_type operator()(_URNG& __g)
|
|
{return (*this)(__g, __p_);}
|
|
template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
|
|
|
|
// property functions
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
vector<result_type> intervals() const {return __p_.intervals();}
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
vector<result_type> densities() const {return __p_.densities();}
|
|
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
param_type param() const {return __p_;}
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
void param(const param_type& __p) {__p_ = __p;}
|
|
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
result_type min() const {return __p_.__b_.front();}
|
|
_LIBCPP_INLINE_VISIBILITY
|
|
result_type max() const {return __p_.__b_.back();}
|
|
|
|
friend _LIBCPP_INLINE_VISIBILITY
|
|
bool operator==(const piecewise_constant_distribution& __x,
|
|
const piecewise_constant_distribution& __y)
|
|
{return __x.__p_ == __y.__p_;}
|
|
friend _LIBCPP_INLINE_VISIBILITY
|
|
bool operator!=(const piecewise_constant_distribution& __x,
|
|
const piecewise_constant_distribution& __y)
|
|
{return !(__x == __y);}
|
|
|
|
template <class _CharT, class _Traits, class _RT>
|
|
friend
|
|
basic_ostream<_CharT, _Traits>&
|
|
operator<<(basic_ostream<_CharT, _Traits>& __os,
|
|
const piecewise_constant_distribution<_RT>& __x);
|
|
|
|
template <class _CharT, class _Traits, class _RT>
|
|
friend
|
|
basic_istream<_CharT, _Traits>&
|
|
operator>>(basic_istream<_CharT, _Traits>& __is,
|
|
piecewise_constant_distribution<_RT>& __x);
|
|
};
|
|
|
|
template<class _RealType>
|
|
typename piecewise_constant_distribution<_RealType>::param_type &
|
|
piecewise_constant_distribution<_RealType>::param_type::operator=
|
|
(const param_type& __rhs)
|
|
{
|
|
// These can throw
|
|
__b_.reserve (__rhs.__b_.size ());
|
|
__densities_.reserve(__rhs.__densities_.size());
|
|
__areas_.reserve (__rhs.__areas_.size());
|
|
|
|
// These can not throw
|
|
__b_ = __rhs.__b_;
|
|
__densities_ = __rhs.__densities_;
|
|
__areas_ = __rhs.__areas_;
|
|
return *this;
|
|
}
|
|
|
|
template<class _RealType>
|
|
void
|
|
piecewise_constant_distribution<_RealType>::param_type::__init()
|
|
{
|
|
// __densities_ contains non-normalized areas
|
|
result_type __total_area = _VSTD::accumulate(__densities_.begin(),
|
|
__densities_.end(),
|
|
result_type());
|
|
for (size_t __i = 0; __i < __densities_.size(); ++__i)
|
|
__densities_[__i] /= __total_area;
|
|
// __densities_ contains normalized areas
|
|
__areas_.assign(__densities_.size(), result_type());
|
|
_VSTD::partial_sum(__densities_.begin(), __densities_.end() - 1,
|
|
__areas_.begin() + 1);
|
|
// __areas_ contains partial sums of normalized areas: [0, __densities_ - 1]
|
|
__densities_.back() = 1 - __areas_.back(); // correct round off error
|
|
for (size_t __i = 0; __i < __densities_.size(); ++__i)
|
|
__densities_[__i] /= (__b_[__i+1] - __b_[__i]);
|
|
// __densities_ now contains __densities_
|
|
}
|
|
|
|
template<class _RealType>
|
|
piecewise_constant_distribution<_RealType>::param_type::param_type()
|
|
: __b_(2),
|
|
__densities_(1, 1.0),
|
|
__areas_(1, 0.0)
|
|
{
|
|
__b_[1] = 1;
|
|
}
|
|
|
|
template<class _RealType>
|
|
template<class _InputIteratorB, class _InputIteratorW>
|
|
piecewise_constant_distribution<_RealType>::param_type::param_type(
|
|
_InputIteratorB __fB, _InputIteratorB __lB, _InputIteratorW __fW)
|
|
: __b_(__fB, __lB)
|
|
{
|
|
if (__b_.size() < 2)
|
|
{
|
|
__b_.resize(2);
|
|
__b_[0] = 0;
|
|
__b_[1] = 1;
|
|
__densities_.assign(1, 1.0);
|
|
__areas_.assign(1, 0.0);
|
|
}
|
|
else
|
|
{
|
|
__densities_.reserve(__b_.size() - 1);
|
|
for (size_t __i = 0; __i < __b_.size() - 1; ++__i, ++__fW)
|
|
__densities_.push_back(*__fW);
|
|
__init();
|
|
}
|
|
}
|
|
|
|
#ifndef _LIBCPP_CXX03_LANG
|
|
|
|
template<class _RealType>
|
|
template<class _UnaryOperation>
|
|
piecewise_constant_distribution<_RealType>::param_type::param_type(
|
|
initializer_list<result_type> __bl, _UnaryOperation __fw)
|
|
: __b_(__bl.begin(), __bl.end())
|
|
{
|
|
if (__b_.size() < 2)
|
|
{
|
|
__b_.resize(2);
|
|
__b_[0] = 0;
|
|
__b_[1] = 1;
|
|
__densities_.assign(1, 1.0);
|
|
__areas_.assign(1, 0.0);
|
|
}
|
|
else
|
|
{
|
|
__densities_.reserve(__b_.size() - 1);
|
|
for (size_t __i = 0; __i < __b_.size() - 1; ++__i)
|
|
__densities_.push_back(__fw((__b_[__i+1] + __b_[__i])*.5));
|
|
__init();
|
|
}
|
|
}
|
|
|
|
#endif // _LIBCPP_CXX03_LANG
|
|
|
|
template<class _RealType>
|
|
template<class _UnaryOperation>
|
|
piecewise_constant_distribution<_RealType>::param_type::param_type(
|
|
size_t __nw, result_type __xmin, result_type __xmax, _UnaryOperation __fw)
|
|
: __b_(__nw == 0 ? 2 : __nw + 1)
|
|
{
|
|
size_t __n = __b_.size() - 1;
|
|
result_type __d = (__xmax - __xmin) / __n;
|
|
__densities_.reserve(__n);
|
|
for (size_t __i = 0; __i < __n; ++__i)
|
|
{
|
|
__b_[__i] = __xmin + __i * __d;
|
|
__densities_.push_back(__fw(__b_[__i] + __d*.5));
|
|
}
|
|
__b_[__n] = __xmax;
|
|
__init();
|
|
}
|
|
|
|
template<class _RealType>
|
|
template<class _URNG>
|
|
_RealType
|
|
piecewise_constant_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
|
|
{
|
|
typedef uniform_real_distribution<result_type> _Gen;
|
|
result_type __u = _Gen()(__g);
|
|
ptrdiff_t __k = _VSTD::upper_bound(__p.__areas_.begin(), __p.__areas_.end(),
|
|
__u) - __p.__areas_.begin() - 1;
|
|
return (__u - __p.__areas_[__k]) / __p.__densities_[__k] + __p.__b_[__k];
|
|
}
|
|
|
|
template <class _CharT, class _Traits, class _RT>
|
|
basic_ostream<_CharT, _Traits>&
|
|
operator<<(basic_ostream<_CharT, _Traits>& __os,
|
|
const piecewise_constant_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);
|
|
size_t __n = __x.__p_.__b_.size();
|
|
__os << __n;
|
|
for (size_t __i = 0; __i < __n; ++__i)
|
|
__os << __sp << __x.__p_.__b_[__i];
|
|
__n = __x.__p_.__densities_.size();
|
|
__os << __sp << __n;
|
|
for (size_t __i = 0; __i < __n; ++__i)
|
|
__os << __sp << __x.__p_.__densities_[__i];
|
|
__n = __x.__p_.__areas_.size();
|
|
__os << __sp << __n;
|
|
for (size_t __i = 0; __i < __n; ++__i)
|
|
__os << __sp << __x.__p_.__areas_[__i];
|
|
return __os;
|
|
}
|
|
|
|
template <class _CharT, class _Traits, class _RT>
|
|
basic_istream<_CharT, _Traits>&
|
|
operator>>(basic_istream<_CharT, _Traits>& __is,
|
|
piecewise_constant_distribution<_RT>& __x)
|
|
{
|
|
typedef piecewise_constant_distribution<_RT> _Eng;
|
|
typedef typename _Eng::result_type result_type;
|
|
__save_flags<_CharT, _Traits> __lx(__is);
|
|
typedef basic_istream<_CharT, _Traits> _Istream;
|
|
__is.flags(_Istream::dec | _Istream::skipws);
|
|
size_t __n;
|
|
__is >> __n;
|
|
vector<result_type> __b(__n);
|
|
for (size_t __i = 0; __i < __n; ++__i)
|
|
__is >> __b[__i];
|
|
__is >> __n;
|
|
vector<result_type> __densities(__n);
|
|
for (size_t __i = 0; __i < __n; ++__i)
|
|
__is >> __densities[__i];
|
|
__is >> __n;
|
|
vector<result_type> __areas(__n);
|
|
for (size_t __i = 0; __i < __n; ++__i)
|
|
__is >> __areas[__i];
|
|
if (!__is.fail())
|
|
{
|
|
swap(__x.__p_.__b_, __b);
|
|
swap(__x.__p_.__densities_, __densities);
|
|
swap(__x.__p_.__areas_, __areas);
|
|
}
|
|
return __is;
|
|
}
|
|
|
|
_LIBCPP_END_NAMESPACE_STD
|
|
|
|
_LIBCPP_POP_MACROS
|
|
|
|
#endif // _LIBCPP___RANDOM_PIECEWISE_CONSTANT_DISTRIBUTION_H
|