PrincipalAxes< DIM, FT > Class Template Reference

Computes the center and inertia axes of a set of 2D or 3D points. More...

#include <easy3d/core/principal_axes.h>

Public Member Functions
void	begin ()
	Begins adding points.
template<typename FT2 >
void	add (const Vec< DIM, FT2 > &p, FT2 weight=FT2(1))
	Adds a point p with a weight. This function supports different types of vectors, e.g. vec3, dvec3, ivec3.
void	end ()
	Ends adding points.
template<typename InputIterator >
void	add (InputIterator first, InputIterator last)
	Adds a set of points (internally it iteratively calls add()).
template<typename FT2 >
Vec< DIM, FT2 >	center () const
	The weighted average of the points. This function supports different types of vectors, e.g. vec3, dvec3, ivec3. To call this function, use. More...
template<typename FT2 >
Vec< DIM, FT2 >	axis (int i) const
	The i_th axis This function supports different types of vectors, e.g. vec3, dvec3, ivec3. To call this function, use. More...
FT	eigen_value (int i) const
	The i_th eigenvalue. More...

Detailed Description

template<int DIM, typename FT = double>
class easy3d::PrincipalAxes< DIM, FT >

Computes the center and inertia axes of a set of 2D or 3D points.

Template Parameters

DIM	dimension (must be 2 or 3).
FT	The type of the floating-point number (float or double). The default type is 'double'.

Note

Using 'float' may result in large errors (accumulated when dealing a large of number coordinates of different scales.

Todo:

Test 2D cases.

Member Function Documentation

axis()

Vec< DIM, FT2 > axis ( int  i ) const

inline

The i_th axis This function supports different types of vectors, e.g. vec3, dvec3, ivec3. To call this function, use.

normal = pca.axis<float>(2);

Note

The eigenvectors are sorted in accordance with eigenvalues stored in the descending order.

center()

Vec< DIM, FT2 > center

inline

The weighted average of the points. This function supports different types of vectors, e.g. vec3, dvec3, ivec3. To call this function, use.

center = pca.center<float>();

eigen_value()

FT eigen_value ( int  i ) const

inline

The i_th eigenvalue.

Note

The eigenvalues are sorted in descending order.

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The documentation for this class was generated from the following file:

• /Users/lnan/Documents/Projects/Easy3D/easy3d/core/principal_axes.h