Newer
Older
Karsten Rink
committed
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
/** \file
* \author Dmitri Naumov
* \date Apr. 2012
* \brief Implementation of Histogram class.
*
*/
#ifndef BASELIB_HISTOGRAM_H
#define BASELIB_HISTOGRAM_H
#include <algorithm>
#include <cmath>
#include <iterator>
#include <ostream>
#include <vector>
namespace BASELIB
{
/** Basic Histogram implementation.
*
* Creates histogram from input data of type \c T.
*/
template <typename T>
class Histogram
{
public:
typedef typename std::vector<T> Data; ///< Underlying input data vector
/// type.
public:
/** Creates histogram of the given element in the range \c [first, last).
*
* Input data is copied into \c std::vector.
*
* \param data Range of elements to create histogram from.
* \param nr_bins Number of bins in histogram.
* \param computeHistogram Compute histogram if set. If not set user must
* call \c update() before accessing data.
*/
template <typename InputIterator>
Histogram(InputIterator first, InputIterator last, const int nr_bins = 16,
const bool computeHistogram = true )
: _data(first, last), _nr_bins(nr_bins)
{
std::sort(_data.begin(), _data.end());
_histogram.resize(_nr_bins);
_min = _data.front();
_max = _data.back();
_bin_width = (_max - _min)/_nr_bins;
_dirty = true;
if (computeHistogram)
update();
}
/** Creates histogram from \c std::vector.
* \param data Input vector.
* \param nr_bins Number of bins in histogram.
* \param computeHistogram Compute histogram if set. If not set user must call
* \c update() before accessing data.
*/
Histogram(std::vector<T> const& data, const unsigned int nr_bins = 16,
const bool computeHistogram = true)
: _data(data), _nr_bins(nr_bins)
{
std::sort(_data.begin(), _data.end());
_histogram.resize(_nr_bins);
_min = _data.front();
_max = _data.back();
_bin_width = (_max - _min)/_nr_bins;
_dirty = true;
if (computeHistogram)
update();
}
/** Updates histogram using sorted \c _data vector.
*
* Start histogram creation with first element. Then find first element in
* the next histogram bin. Number of elments in the bin is the difference
* between these two iterators.
* \verbatim
[0.1, 0.2, ..., 0.7 , ..., 0.7+binWidth = 0.9, 1.0 , ..., last]
it itEnd - 1 itEnd
\endverbatim
*/
void
update()
{
if (!_dirty)
return;
_bin_width = (_max - _min)/_nr_bins;
typedef typename Data::const_iterator DataCI;
DataCI it = _data.begin();
DataCI itEnd;
for (unsigned int bin = 0; bin < _nr_bins; bin++) {
itEnd = std::upper_bound(it, (DataCI)_data.end(),
_min + (bin + 1) * _bin_width);
_histogram[bin] = std::distance(it, itEnd);
it = itEnd;
}
_dirty = false;
}
void setMinimum(const T& minimum) { _min = minimum; _dirty = true; }
void setMaximum(const T& maximum) { _max = maximum; _dirty = true; }
const Data& getSortedData() const { return _data; }
const std::vector<std::size_t>& getBinCounts() const { return _histogram; }
Karsten Rink
committed
const unsigned int& getNrBins() const { return _nr_bins; }
const T& getMinimum() const { return _min; }
const T& getMaximum() const { return _max; }
const T& getBinWidth() const { return _bin_width; }
void
prettyPrint(std::ostream& os, const unsigned int line_width = 16) const
{
const std::size_t count_max = *std::max_element(_histogram.begin(), _histogram.end());
Karsten Rink
committed
for (unsigned int bin = 0; bin < _nr_bins; ++bin) {
os << "[" << _min + bin * _bin_width << ", " << _min + (bin + 1) * _bin_width << ")\t";
os << _histogram[bin] << "\t";
const int n_stars = std::ceil(line_width * ((double)_histogram[bin]/count_max));
for (int star = 0; star < n_stars; star++)
os << "*";
os << "\n";
}
}
protected:
Data _data;
const unsigned int _nr_bins;
Karsten Rink
committed
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
T _min, _max; ///< Minimum and maximum input data values.
T _bin_width;
private:
bool _dirty; ///< When set \c update() will recompute histogram.
};
/** Writes histogram to output stream.
*
* Writes histogram properties in this order:
* number of bins, minimum, maximum, bin0 count, ..., binN-1 count.
*/
template <typename T>
std::ostream&
operator<<(std::ostream& os, const Histogram<T>& h)
{
os << h.getNrBins() << " "
<< h.getMinimum() << " "
<< h.getMaximum() << " ";
std::copy(h.getBinCounts().begin(), h.getBinCounts().end(),
std::ostream_iterator<T>(os, " "));
return os << std::endl;
}
} // namespace BASELIB
#endif // BASELIB_HISTOGRAM_H