Examples/Statistics/PointSetToAdaptor.cxx

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// Software Guide : BeginLatex
//
// We will describe how to use \doxygen{PointSet} as a \code{Sample}
// using an adaptor in this example.
//
// \index{itk::Sample!PointSetToListSampleAdaptor}
//
// \subdoxygen{Statistics}{PointSetToListSampleAdaptor} class requires the type
// of input \doxygen{PointSet} object. The \doxygen{PointSet} class is an
// associative data container. Each point in a \code{PointSet} object can have
// its associated data value (optional). For the statistics subsystem, current
// implementation of \code{PointSetToListSampleAdaptor} takes only the point part
// into consideration. In other words, the measurement vectors from a
// \code{PointSetToListSampleAdaptor} object are points from the \code{PointSet}
// object that is plugged-into the adaptor object.
//
// To use, an \doxygen{PointSetToListSampleAdaptor} object, we include the
// header file for the class.
//
// Software Guide : EndLatex


// Software Guide : BeginCodeSnippet
#include "itkPointSetToListSampleAdaptor.h"
// Software Guide : EndCodeSnippet

// Software Guide : BeginLatex
//
// Since, we are using an adaptor, we also include the header file for
// the \doxygen{PointSet} class.
//
// Software Guide :EndLatex

// Software Guide : BeginCodeSnippet
#include "itkPointSet.h"
// Software Guide : EndCodeSnippet

int main()
{
  // Software Guide : BeginLatex
  //
  // We assume you already know how to create an \doxygen{PointSet} object. The
  // following code snippet will create a 2D image of float pixels filled
  // with random values.
  //
  // Software Guide :EndLatex

  // Software Guide : BeginCodeSnippet
  using FloatPointSet2DType = itk::PointSet<float,2>;

  itk::RandomPointSetSource<FloatPointSet2DType>::Pointer random;
  random = itk::RandomPointSetSource<FloatPointSet2DType>::New();
  random->SetMin(0.0);
  random->SetMax(1000.0);

  unsigned long size[2] = {20, 20};
  random->SetSize(size);
  float spacing[2] = {0.7, 2.1};
  random->SetSpacing( spacing );
  float origin[2] = {15, 400};
  random->SetOrigin( origin );
  // Software Guide : EndCodeSnippet

  // Software Guide : BeginLatex
  //
  // We now have an \doxygen{PointSet} object and need to cast it to an
  // \doxygen{PointSet} object with array type (anything derived from
  // the \doxygen{FixedArray} class) pixels.
  //
  // Since, the \doxygen{PointSet} object's pixel type is \code{float},
  // We will use single element \code{float} \doxygen{FixedArray}
  // as our measurement vector type. And that will also be our pixel
  // type for the cast filter.
  //
  // Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
  using MeasurementVectorType = itk::FixedArray< float, 1 >;
  using ArrayPointSetType = itk::PointSet< MeasurementVectorType, 2 >;
  using CasterType = itk::ScalarToArrayCastPointSetFilter< FloatPointSet2DType,
                             ArrayPointSetType >;

  CasterType::Pointer caster = CasterType::New();
  caster->SetInput( random->GetOutput() );
  caster->Update();
  // Software Guide : EndCodeSnippet

  // Software Guide : BeginLatex
  //
  // Up to now, we spend most of time to prepare an \doxygen{PointSet} object
  // suitable for the adaptor. Actually, the hard part of this example is
  // done. Now, we must define an adaptor with the image type and
  // instantiate an object.
  //
  // Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
  using SampleType = itk::Statistics::PointSetToListSampleAdaptor<
                                               ArrayPointSetType >;
  SampleType::Pointer sample = SampleType::New();
  // Software Guide : EndCodeSnippet

  // Software Guide : BeginLatex
  //
  // The final thing we have to is to plug-in the image object to the adaptor.
  // After that, we can use the common methods and iterator interfaces
  // shown in \ref{sec:SampleInterface}.
  //
  // Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
  sample->SetPointSet( caster->GetOutput() );
  // Software Guide : EndCodeSnippet

  return EXIT_SUCCESS;
}