Distance Between Points#

Synopsis#

Compute the distance between two 3D points. This can easily be extended to ND by changing the constant Dimension.

Results#

Output:

Dist: 1.73205
Dist2: 3

Code#

C++#

#include "itkPoint.h"
#include "itkMath.h"

#include <iostream>

int
main()
{
  constexpr unsigned int Dimension = 3;
  using CoordType = double;

  using PointType = itk::Point<CoordType, Dimension>;

  PointType p0;
  p0[0] = 0.0;
  p0[1] = 0.0;
  p0[2] = 0.0;

  PointType p1;
  p1[0] = 1.0;
  p1[1] = 1.0;
  p1[2] = 1.0;

  PointType::RealType dist = p0.EuclideanDistanceTo(p1);
  std::cout << "Dist: " << dist << std::endl;

  if (dist != p1.EuclideanDistanceTo(p0))
  {
    std::cerr << "p0.EuclideanDistanceTo(p1) != p1.EuclideanDistanceTo(p0)" << std::endl;
    return EXIT_FAILURE;
  }

  if (p1.EuclideanDistanceTo(p1) != 0.)
  {
    std::cerr << "p1.EuclideanDistanceTo(p1) != 0." << std::endl;
    return EXIT_FAILURE;
  }

  PointType::RealType dist2 = p0.SquaredEuclideanDistanceTo(p1);
  std::cout << "Dist2: " << dist2 << std::endl;

  if (itk::Math::abs(dist2 - dist * dist) < itk::Math::eps)
  {
    std::cerr << "dist2 != dist * dist" << std::endl;
    return EXIT_FAILURE;
  }

  return EXIT_SUCCESS;
}

Classes demonstrated#

template<typename TCoordRep, unsigned int NPointDimension = 3> class Point : public itk::FixedArray<TCoordRep, NPointDimension>

A templated class holding a geometric point in n-Dimensional space.

Point is a templated class that holds a set of coordinates (components). Point can be used as the data type held at each pixel in an Image or at each vertex of an Mesh. The template parameter T can be any data type that behaves like a primitive (or atomic) data type (int, short, float, complex). The NPointDimension defines the number of components in the point array.

See

Image

See

Mesh

See

Vector

See

CovariantVector

See