ITK  5.0.0
Insight Segmentation and Registration Toolkit
Examples/Statistics/PointSetToListSampleAdaptor.cxx
/*=========================================================================
*
* 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
//
// We will describe how to use \doxygen{PointSet} as a
// \subdoxygen{Statistics}{Sample} using an adaptor in this example.
//
// \index{itk::Statistics::PointSetToListSampleAdaptor}
//
// The \subdoxygen{Statistics}{PointSetToListSampleAdaptor} class requires a
// PointSet as input. The PointSet class is an associative data
// container. Each point in a PointSet object can have an associated
// optional data value. For the statistics subsystem, the current
// implementation of PointSetToListSampleAdaptor takes only the point part
// into consideration. In other words, the measurement vectors from a
// PointSetToListSampleAdaptor object are points from the PointSet
// object that is plugged into the adaptor object.
//
// To use an PointSetToListSampleAdaptor class, we include the header file for the
// class.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// Since we are using an adaptor, we also include the header file for
// the PointSet class.
//
// Software Guide :EndLatex
// Software Guide : BeginCodeSnippet
#include "itkPointSet.h"
#include "itkVector.h"
// Software Guide : EndCodeSnippet
int main()
{
// Software Guide : BeginLatex
//
// Next we create a PointSet object.
// The following code
// snippet will create a PointSet object that stores points (its coordinate
// value type is float) in 3D space.
//
// Software Guide :EndLatex
// Software Guide : BeginCodeSnippet
using PointSetType = itk::PointSet< short >;
PointSetType::Pointer pointSet = PointSetType::New();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// Note that the \code{short} type used in the declaration of
// \code{PointSetType} pertains to the pixel type associated with every
// point, not to the type used to represent point coordinates. If we want
// to change the type of the point in terms of the coordinate value and/or
// dimension, we have to modify the \code{TMeshTraits} (one of the optional
// template arguments for the \code{PointSet} class). The easiest way of
// creating a custom mesh traits instance is to specialize the existing
// \doxygen{DefaultStaticMeshTraits}. By specifying the \code{TCoordRep}
// template argument, we can change the coordinate value type of a point.
// By specifying the \code{VPointDimension} template argument, we can
// change the dimension of the point. As mentioned earlier, a
// \code{PointSetToListSampleAdaptor} object cares only about the points, and the
// type of measurement vectors is the type of points.
//
// Software Guide : EndLatex
// Software Guide : BeginLatex
//
// To make the example a little bit realistic, we add two points
// into the \code{pointSet}.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
point[0] = 1.0;
point[1] = 2.0;
point[2] = 3.0;
pointSet->SetPoint( 0UL, point);
point[0] = 2.0;
point[1] = 4.0;
point[2] = 6.0;
pointSet->SetPoint( 1UL, point );
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// Now we have a PointSet object with two points in it. The
// PointSet is ready to be plugged into the adaptor.
// First, we create an instance of the PointSetToListSampleAdaptor class
// with the type of the input PointSet object.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
using SampleType =
SampleType::Pointer sample = SampleType::New();
// Software Guide : EndCodeSnippet
// Software Guide : BeginLatex
//
// Second, all we have to do is
// plug in the PointSet object to the adaptor. After that,
// we can use the common methods and iterator interfaces shown in
// Section~\ref{sec:SampleInterface}.
//
// Software Guide : EndLatex
// Software Guide : BeginCodeSnippet
sample->SetPointSet( pointSet );
SampleType::Iterator iter = sample->Begin();
while( iter != sample->End() )
{
std::cout << "id = " << iter.GetInstanceIdentifier()
<< "\t measurement vector = "
<< iter.GetMeasurementVector()
<< "\t frequency = "
<< iter.GetFrequency()
<< std::endl;
++iter;
}
// Software Guide : EndCodeSnippet
return EXIT_SUCCESS;
}