# 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;
p0 = 0.0;
p0 = 0.0;

PointType p1;
p1 = 1.0;
p1 = 1.0;
p1 = 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

Matrix

ITK Sphinx Examples: