#include <CGAL/Classification/Local_eigen_analysis.h>

Definition

Class that precomputes and stores the eigenvectors and eigenvalues of the covariance matrices of all points of a point set using a local neighborhood.

This class can be used to compute eigen features (see Predefined Features) and to estimate local normal vectors and tangent planes.

Public Types
using	Eigenvalues = std::array< float, 3 >
	Eigenvalues (sorted in ascending order)

Named Constructors
template<typename PointRange , typename PointMap , typename NeighborQuery , typename ConcurrencyTag , typename DiagonalizeTraits >
static Local_eigen_analysis	create_from_point_set (const PointRange &input, PointMap point_map, const NeighborQuery &neighbor_query, const ConcurrencyTag &=ConcurrencyTag(), const DiagonalizeTraits &=DiagonalizeTraits())
	computes the local eigen analysis of an input point set based on a local neighborhood. More...

template<typename FaceListGraph , typename NeighborQuery , typename ConcurrencyTag , typename DiagonalizeTraits >
static Local_eigen_analysis	create_from_face_graph (const FaceListGraph &input, const NeighborQuery &neighbor_query, const ConcurrencyTag &=ConcurrencyTag(), const DiagonalizeTraits &=DiagonalizeTraits())
	computes the local eigen analysis of an input face graph based on a local neighborhood. More...

template<typename ClusterRange , typename ConcurrencyTag , typename DiagonalizeTraits >
static Local_eigen_analysis	create_from_point_clusters (const ClusterRange &input, const ConcurrencyTag &=ConcurrencyTag(), const DiagonalizeTraits &=DiagonalizeTraits())
	computes the local eigen analysis of an input set of point clusters based on a local neighborhood. More...

Analysis
template<typename GeomTraits >
GeomTraits::Vector_3	normal_vector (std::size_t index) const
	returns the estimated unoriented normal vector of the point at position `index`. More...

template<typename GeomTraits >
GeomTraits::Plane_3	plane (std::size_t index) const
	returns the estimated local tangent plane of the point at position `index`. More...

Eigenvalues	eigenvalue (std::size_t index) const
	returns the normalized eigenvalues of the point at position `index`.

Member Function Documentation

◆ create_from_face_graph()

template<typename FaceListGraph , typename NeighborQuery , typename ConcurrencyTag , typename DiagonalizeTraits >

static Local_eigen_analysis CGAL::Classification::Local_eigen_analysis::create_from_face_graph	(	const FaceListGraph &	input,
		const NeighborQuery &	neighbor_query,
		const ConcurrencyTag &	= `ConcurrencyTag()`,
		const DiagonalizeTraits &	= `DiagonalizeTraits()`
	)

static

computes the local eigen analysis of an input face graph based on a local neighborhood.

Template Parameters

FaceListGraph	model of `FaceListGraph`.
NeighborQuery	model of `NeighborQuery`
ConcurrencyTag	enables sequential versus parallel algorithm. Possible values are `Parallel_tag` (default value if CGAL is linked with TBB) or `Sequential_tag` (default value otherwise).
DiagonalizeTraits	model of `DiagonalizeTraits` used for matrix diagonalization. It can be omitted: if Eigen 3 (or greater) is available and `CGAL_EIGEN3_ENABLED` is defined then an overload using `Eigen_diagonalize_traits` is provided. Otherwise, the internal implementation `Diagonalize_traits` is used.

Parameters

input	face graph.
neighbor_query	object used to access neighborhoods of points.

◆ create_from_point_clusters()

template<typename ClusterRange , typename ConcurrencyTag , typename DiagonalizeTraits >

static Local_eigen_analysis CGAL::Classification::Local_eigen_analysis::create_from_point_clusters	(	const ClusterRange &	input,
		const ConcurrencyTag &	= `ConcurrencyTag()`,
		const DiagonalizeTraits &	= `DiagonalizeTraits()`
	)

static

computes the local eigen analysis of an input set of point clusters based on a local neighborhood.

Template Parameters

ClusterRange	model of `ConstRange`. Its iterator type is `RandomAccessIterator` and its value type is the key type of `PointMap`.
ConcurrencyTag	enables sequential versus parallel algorithm. Possible values are `Parallel_tag` (default value if CGAL is linked with TBB) or `Sequential_tag` (default value otherwise).
DiagonalizeTraits	model of `DiagonalizeTraits` used for matrix diagonalization. It can be omitted: if Eigen 3 (or greater) is available and `CGAL_EIGEN3_ENABLED` is defined then an overload using `Eigen_diagonalize_traits` is provided. Otherwise, the internal implementation `Diagonalize_traits` is used.

Parameters

input cluster range.

◆ create_from_point_set()

template<typename PointRange , typename PointMap , typename NeighborQuery , typename ConcurrencyTag , typename DiagonalizeTraits >

static Local_eigen_analysis CGAL::Classification::Local_eigen_analysis::create_from_point_set	(	const PointRange &	input,
		PointMap	point_map,
		const NeighborQuery &	neighbor_query,
		const ConcurrencyTag &	= `ConcurrencyTag()`,
		const DiagonalizeTraits &	= `DiagonalizeTraits()`
	)

static

computes the local eigen analysis of an input point set based on a local neighborhood.

Template Parameters

PointRange	model of `ConstRange`. Its iterator type is `RandomAccessIterator` and its value type is the key type of `PointMap`.
PointMap	model of `ReadablePropertyMap` whose key type is the value type of the iterator of `PointRange` and value type is `CGAL::Point_3`.
NeighborQuery	model of `NeighborQuery`
ConcurrencyTag	enables sequential versus parallel algorithm. Possible values are `Parallel_tag` (default value if CGAL is linked with TBB) or `Sequential_tag` (default value otherwise).
DiagonalizeTraits	model of `DiagonalizeTraits` used for matrix diagonalization. It can be omitted if Eigen 3 (or greater) is available and `CGAL_EIGEN3_ENABLED` is defined. In that case, an overload using `Eigen_diagonalize_traits` is provided.

Parameters

input	point range.
point_map	property map to access the input points.
neighbor_query	object used to access neighborhoods of points.

Examples:: Classification/example_feature.cpp.

◆ normal_vector()

template<typename GeomTraits >

GeomTraits::Vector_3 CGAL::Classification::Local_eigen_analysis::normal_vector ( std::size_t index ) const

returns the estimated unoriented normal vector of the point at position index.

Template Parameters

GeomTraits model of CGAL Kernel.

◆ plane()

template<typename GeomTraits >

GeomTraits::Plane_3 CGAL::Classification::Local_eigen_analysis::plane ( std::size_t index ) const

returns the estimated local tangent plane of the point at position index.

Template Parameters

GeomTraits model of CGAL Kernel.

Definition

Public Types

Named Constructors

Analysis

Member Function Documentation

◆ create_from_face_graph()

◆ create_from_point_clusters()

◆ create_from_point_set()

◆ normal_vector()

◆ plane()