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
|
/*=========================================================================
*
* Copyright Insight Software Consortium
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0.txt
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*=========================================================================*/
// Software Guide : BeginLatex
//
// \index{Statistics!Importing ListSample to Histogram}
// \index{itk::Statistics::List\-Sample\-To\-Histogram\-Filter}
//
// Sometimes we want to work with a histogram instead of a list of
// measurement vectors (e.g. \subdoxygen{Statistics}{ListSample},
// \subdoxygen{Statistics}{ImageToListSampleAdaptor}, or
// \subdoxygen{Statistics}{PointSetToListSample}) to use less memory or to
// perform a particular type od analysis. In such cases, we can import data
// from a sample type to a \subdoxygen{Statistics}{Histogram} object
// using the \subdoxygen{Statistics}{SampleToHistogramFiler}.
//
// We use a ListSample object as the input for the filter. We include the
// header files for the ListSample and Histogram classes, as well as the
// filter.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
#include "itkListSample.h"
#include "itkHistogram.h"
#include "itkSampleToHistogramFilter.h"
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// We need another header for the type of the measurement vectors. We are
// going to use the \doxygen{Vector} class which is a subclass of the
// \doxygen{FixedArray} in this example.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
#include "itkVector.h"
// Software Guide : EndCodeSnippet
int main()
{
// Software Guide : BeginLatex
//
// The following code snippet creates a ListSample object with
// two-component \code{int} measurement vectors and put the measurement
// vectors: [1,1] - 1 time, [2,2] - 2 times, [3,3] - 3 times, [4,4] - 4
// times, [5,5] - 5 times into the \code{listSample}.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
typedef int MeasurementType;
const unsigned int MeasurementVectorLength = 2;
typedef itk::Vector< MeasurementType , MeasurementVectorLength >
MeasurementVectorType;
typedef itk::Statistics::ListSample< MeasurementVectorType > ListSampleType;
ListSampleType::Pointer listSample = ListSampleType::New();
listSample->SetMeasurementVectorSize( MeasurementVectorLength );
MeasurementVectorType mv;
for (unsigned int i = 1; i < 6; ++i)
{
for (unsigned int j = 0; j < 2; ++j)
{
mv[j] = ( MeasurementType ) i;
}
for (unsigned int j = 0; j < i; ++j)
{
listSample->PushBack(mv);
}
}
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// Here, we set up the size and bound of the output histogram.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
typedef float HistogramMeasurementType;
const unsigned int numberOfComponents = 2;
typedef itk::Statistics::Histogram< HistogramMeasurementType >
HistogramType;
HistogramType::SizeType size( numberOfComponents );
size.Fill(5);
HistogramType::MeasurementVectorType lowerBound( numberOfComponents );
HistogramType::MeasurementVectorType upperBound( numberOfComponents );
lowerBound[0] = 0.5;
lowerBound[1] = 0.5;
upperBound[0] = 5.5;
upperBound[1] = 5.5;
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// Now, we set up the \code{SampleToHistogramFilter} object by passing
// \code{listSample} as the input and initializing the histogram size
// and bounds with the \code{SetHistogramSize()},
// \code{SetHistogramBinMinimum()}, and \code{SetHistogramBinMaximum()}
// methods. We execute the filter by calling the \code{Update()}
// method.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
typedef itk::Statistics::SampleToHistogramFilter< ListSampleType,
HistogramType > FilterType;
FilterType::Pointer filter = FilterType::New();
filter->SetInput( listSample );
filter->SetHistogramSize( size );
filter->SetHistogramBinMinimum( lowerBound );
filter->SetHistogramBinMaximum( upperBound );
filter->Update();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// The \code{Size()} and \code{GetTotalFrequency()} methods return the same
// values as the \code{sample} does.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
const HistogramType* histogram = filter->GetOutput();
HistogramType::ConstIterator iter = histogram->Begin();
while ( iter != histogram->End() )
{
std::cout << "Measurement vectors = " << iter.GetMeasurementVector()
<< " frequency = " << iter.GetFrequency() << std::endl;
++iter;
}
std::cout << "Size = " << histogram->Size() << std::endl;
std::cout << "Total frequency = "
<< histogram->GetTotalFrequency() << std::endl;
// Software Guide : EndCodeSnippet
return EXIT_SUCCESS;
}
|
