Ticket #12832: histogram.h

File histogram.h, 5.5 KB (added by georg@…, 6 years ago)

histogram with fixed limits

Line 
1///////////////////////////////////////////////////////////////////////////////
2// histogram.h
3//
4// Copyright 2006 Daniel Egloff, Olivier Gygi. Distributed under the Boost
5// Software License, Version 1.0. (See accompanying file
6// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
7//
8// Georg Gast (12.02.2017)
9// based on density.hpp
10
11#ifndef BOOST_ACCUMULATORS_STATISTICS_HISTOGRAM
12#define BOOST_ACCUMULATORS_STATISTICS_HISTOGRAM
13
14#include <boost/accumulators/accumulators_fwd.hpp>
15#include <boost/accumulators/framework/accumulator_base.hpp>
16#include <boost/accumulators/framework/depends_on.hpp>
17#include <boost/accumulators/framework/extractor.hpp>
18#include <boost/accumulators/framework/parameters/sample.hpp>
19#include <boost/accumulators/numeric/functional.hpp>
20#include <boost/accumulators/statistics_fwd.hpp>
21#include <boost/mpl/placeholders.hpp>
22#include <boost/parameter/keyword.hpp>
23#include <boost/range.hpp>
24#include <functional>
25#include <limits>
26#include <vector>
27
28namespace boost
29{
30namespace accumulators
31{
32
33///////////////////////////////////////////////////////////////////////////////
34// cache_size and num_bins named parameters
35//
36BOOST_PARAMETER_NESTED_KEYWORD(tag, histogram_limit_low, limit_low)
37BOOST_PARAMETER_NESTED_KEYWORD(tag, histogram_limit_high, limit_high)
38BOOST_PARAMETER_NESTED_KEYWORD(tag, histogram_num_bins, num_bins)
39
40BOOST_ACCUMULATORS_IGNORE_GLOBAL(histogram_limit_low)
41BOOST_ACCUMULATORS_IGNORE_GLOBAL(histogram_limit_high)
42BOOST_ACCUMULATORS_IGNORE_GLOBAL(histogram_num_bins)
43
44namespace impl
45{
46///////////////////////////////////////////////////////////////////////////////
47// histogram_impl
48// histogram
49/**
50 @brief Histogram
51
52 Just a simple histogram with out averaging or anything else
53
54 @param histogram_limit_low lower limit of the histogram
55 @param histogram_limit_high high limit of the histogram
56 @param histogram_num_bins Number of bins (two additional bins collect
57 under- and overflow samples).
58*/
59template <typename Sample>
60struct histogram_impl : accumulator_base
61{
62 typedef typename numeric::functional::fdiv<Sample, std::size_t>::result_type
63 float_type;
64 typedef std::vector<std::pair<float_type, float_type>> histogram_type;
65 typedef std::vector<float_type> array_type;
66 // for boost::result_of
67 typedef iterator_range<typename histogram_type::iterator> result_type;
68
69 template <typename Args>
70 histogram_impl(Args const &args)
71 : num_bins(args[histogram_num_bins]),
72 limit_low(args[histogram_limit_low]),
73 limit_high(args[histogram_limit_high]),
74 samples_in_bin(num_bins + 2, 0.), bin_positions(num_bins + 2),
75 histogram(
76 num_bins + 2,
77 std::make_pair(
78 numeric::fdiv(args[sample | Sample()], (std::size_t)1),
79 numeric::fdiv(args[sample | Sample()], (std::size_t)1))),
80 is_dirty(true)
81 {
82 float_type bin_size =
83 numeric::fdiv(this->limit_high - this->limit_low, this->num_bins);
84
85 // determine bin positions (their lower bounds)
86 for (std::size_t i = 0; i < this->num_bins + 2; ++i)
87 {
88 this->bin_positions[i] = this->limit_low + (i - 1.) * bin_size;
89 }
90 }
91
92 template <typename Args>
93 void operator()(Args const &args)
94 {
95 this->is_dirty = true;
96
97 // Add each subsequent sample to the correct bin
98 if (args[sample] < this->bin_positions[1])
99 {
100 ++(this->samples_in_bin[0]);
101 }
102 else if (args[sample] >= this->bin_positions[this->num_bins + 1])
103 {
104 ++(this->samples_in_bin[this->num_bins + 1]);
105 }
106 else
107 {
108 typename array_type::iterator it =
109 std::upper_bound(this->bin_positions.begin(),
110 this->bin_positions.end(), args[sample]);
111
112 std::size_t d = std::distance(this->bin_positions.begin(), it);
113 ++(this->samples_in_bin[d - 1]);
114 }
115 }
116
117 template <typename Args>
118 result_type result(Args const &args) const
119 {
120 if (this->is_dirty)
121 {
122 this->is_dirty = false;
123
124 // creates a vector of std::pair where each pair i holds
125 // the values bin_positions[i] (x-axis of histogram) and
126 // samples_in_bin[i] (y-axis of histogram).
127
128 for (std::size_t i = 0; i < this->num_bins + 2; ++i)
129 {
130 this->histogram[i] = std::make_pair(this->bin_positions[i],
131 this->samples_in_bin[i]);
132 }
133 }
134 // returns a range of pairs
135 return make_iterator_range(this->histogram);
136 }
137
138private:
139 std::size_t num_bins; // number of bins
140 float_type limit_low; // the lower limit
141 float_type limit_high; // the high limit
142 array_type samples_in_bin; // number of samples in each bin
143 array_type bin_positions; // lower bounds of bins
144 mutable histogram_type histogram; // histogram
145 mutable bool is_dirty;
146};
147
148} // namespace impl
149
150///////////////////////////////////////////////////////////////////////////////
151// tag::histogram
152//
153namespace tag
154{
155struct histogram : depends_on<>,
156 histogram_limit_low,
157 histogram_limit_high,
158 histogram_num_bins
159{
160 /// INTERNAL ONLY
161 ///
162 typedef accumulators::impl::histogram_impl<mpl::_1> impl;
163
164#ifdef BOOST_ACCUMULATORS_DOXYGEN_INVOKED
165 /// tag::histogram::limit_low named parameter
166 /// tag::histogram::limit_high named parameter
167 /// tag::histogram::num_bins named parameter
168 static boost::parameter::keyword<histogram_limit_low> const limit_low;
169 static boost::parameter::keyword<histogram_limit_high> const limit_high;
170 static boost::parameter::keyword<histogram_num_bins> const num_bins;
171#endif
172};
173}
174
175///////////////////////////////////////////////////////////////////////////////
176// extract::histogram
177//
178namespace extract
179{
180extractor<tag::histogram> const histogram = {};
181
182BOOST_ACCUMULATORS_IGNORE_GLOBAL(histogram)
183}
184
185using extract::histogram;
186}
187} // namespace boost::accumulators
188
189#endif // BOOST_ACCUMULATORS_STATISTICS_HISTOGRAM