1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
|
//===----------------------------------------------------------------------===//
//
// 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
|
