#include <deal.II/base/quadrature_lib.h>

Inheritance diagram for QSorted< dim >:

Public Member Functions
	QSorted (const Quadrature< dim > &quad)

Public Member Functions inherited from Quadrature< dim >
	Quadrature (const unsigned int n_quadrature_points=0)

	Quadrature (const SubQuadrature &, const Quadrature< 1 > &)

	Quadrature (const Quadrature< dim !=1 ? 1 :0 > &quadrature_1d)

	Quadrature (const Quadrature< dim > &q)

	Quadrature (Quadrature< dim > &&) noexcept=default

	Quadrature (const std::vector< Point< dim >> &points, const std::vector< double > &weights)

	Quadrature (const std::vector< Point< dim >> &points)

	Quadrature (const Point< dim > &point)

virtual	~Quadrature () override=default

Quadrature &	operator= (const Quadrature< dim > &)

Quadrature &	operator= (Quadrature< dim > &&)=default

bool	operator== (const Quadrature< dim > &p) const

void	initialize (const std::vector< Point< dim >> &points, const std::vector< double > &weights)

unsigned int	size () const

const Point< dim > &	point (const unsigned int i) const

const std::vector< Point< dim > > &	get_points () const

double	weight (const unsigned int i) const

const std::vector< double > &	get_weights () const

std::size_t	memory_consumption () const

template<class Archive >
void	serialize (Archive &ar, const unsigned int version)

bool	is_tensor_product () const

const std::array< Quadrature< 1 >, dim > &	get_tensor_basis () const

	Quadrature (const unsigned int n_q)

Public Member Functions inherited from Subscriptor
	Subscriptor ()

	Subscriptor (const Subscriptor &)

	Subscriptor (Subscriptor &&) noexcept

virtual	~Subscriptor ()

Subscriptor &	operator= (const Subscriptor &)

Subscriptor &	operator= (Subscriptor &&) noexcept

void	subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const

void	unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const

unsigned int	n_subscriptions () const

template<typename StreamType >
void	list_subscribers (StreamType &stream) const

void	list_subscribers () const

template<class Archive >
void	serialize (Archive &ar, const unsigned int version)

Private Member Functions
bool	compare_weights (const unsigned int a, const unsigned int b) const

Additional Inherited Members
Public Types inherited from Quadrature< dim >
using	SubQuadrature = Quadrature< dim - 1 >

Static Public Member Functions inherited from Subscriptor
static ::ExceptionBase &	ExcInUse (int arg1, std::string arg2, std::string arg3)

static ::ExceptionBase &	ExcNoSubscriber (std::string arg1, std::string arg2)

Protected Attributes inherited from Quadrature< dim >
std::vector< Point< dim > >	quadrature_points

std::vector< double >	weights

bool	is_tensor_product_flag

std::unique_ptr< std::array< Quadrature< 1 >, dim > >	tensor_basis

Detailed Description

template<int dim>
class QSorted< dim >

Sorted Quadrature. Given an arbitrary quadrature formula, this class generates a quadrature formula where the quadrature points are ordered according the weights, from those with smaller corresponding weight, to those with higher corresponding weights. This might be necessary, for example, when integrating high order polynomials, since in these cases you might sum very big numbers with very small numbers, and summation is not stable if the numbers to sum are not close to each other.

Definition at line 391 of file quadrature_lib.h.

Constructor & Destructor Documentation

◆ QSorted()

template<int dim>

QSorted< dim >::QSorted ( const Quadrature< dim > & quad )

The constructor takes an arbitrary quadrature formula quad and sorts its points and weights according to ascending weights.

Definition at line 769 of file quadrature_lib.cc.

Member Function Documentation

◆ compare_weights()

template<int dim>

bool QSorted< dim >::compare_weights	(	const unsigned int	a,
		const unsigned int	b
	)		const

private

A rule for std::sort to reorder pairs of points and weights. a and b are indices into the weights array and the result will be determined by comparing the weights.

Definition at line 801 of file quadrature_lib.cc.

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

include/deal.II/base/quadrature_lib.h
source/base/quadrature_lib.cc

Public Member Functions

Private Member Functions