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/*=========================================================================
Program: Insight Segmentation & Registration Toolkit
Module: ListSampleToHistogramFilter.cxx
Language: C++
Date: $Date$
Version: $Revision$
Copyright (c) Insight Software Consortium. All rights reserved.
See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the above copyright notices for more information.
=========================================================================*/
#if defined(_MSC_VER)
#pragma warning ( disable : 4786 )
#endif
// 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}{ImageToListAdaptor}, 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 list type sample to a \subdoxygen{Statistics}{Histogram} object
// using the \subdoxygen{Statistics}{ListSampleToHistogramFilter}.
//
// 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 "itkListSampleToHistogramFilter.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 create a Histogram object with equal interval bins using the
// \code{Initalize()} method.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
typedef float HistogramMeasurementType;
typedef itk::Statistics::Histogram< HistogramMeasurementType, 2 >
HistogramType;
HistogramType::Pointer histogram = HistogramType::New();
HistogramType::SizeType size;
size.Fill(5);
HistogramType::MeasurementVectorType lowerBound;
HistogramType::MeasurementVectorType upperBound;
lowerBound[0] = 0.5;
lowerBound[1] = 0.5;
upperBound[0] = 5.5;
upperBound[1] = 5.5;
histogram->Initialize( size, lowerBound, upperBound );
// 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
typedef itk::Statistics::ListSampleToHistogramFilter< ListSampleType,
HistogramType > FilterType;
FilterType::Pointer filter = FilterType::New();
filter->SetListSample( listSample );
filter->SetHistogram( histogram );
filter->Update();
HistogramType::Iterator 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 0;
}
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