libMesh::QGauss Class Reference

This class implements specific orders of Gauss quadrature. More...

#include <quadrature_gauss.h>

Inheritance diagram for libMesh::QGauss:

Public Member Functions
	QGauss (unsigned int dim, Order order=INVALID_ORDER)
	Constructor. More...
	QGauss (const QGauss &)=default
	Copy/move ctor, copy/move assignment operator, and destructor are all explicitly defaulted for this simple class. More...
	QGauss (QGauss &&)=default
QGauss &	operator= (const QGauss &)=default
QGauss &	operator= (QGauss &&)=default
virtual	~QGauss ()=default
virtual QuadratureType	type () const override
ElemType	get_elem_type () const
unsigned int	get_p_level () const
unsigned int	n_points () const
unsigned int	get_dim () const
const std::vector< Point > &	get_points () const
std::vector< Point > &	get_points ()
const std::vector< Real > &	get_weights () const
std::vector< Real > &	get_weights ()
Point	qp (const unsigned int i) const
Real	w (const unsigned int i) const
virtual void	init (const ElemType type=INVALID_ELEM, unsigned int p_level=0)
	Initializes the data structures for a quadrature rule for an element of type type. More...
virtual void	init (const Elem &elem, const std::vector< Real > &vertex_distance_func, unsigned int p_level=0)
	Initializes the data structures for an element potentially "cut" by a signed distance function. More...
Order	get_order () const
void	print_info (std::ostream &os=libMesh::out) const
	Prints information relevant to the quadrature rule, by default to libMesh::out. More...
void	scale (std::pair< Real, Real > old_range, std::pair< Real, Real > new_range)
	Maps the points of a 1D quadrature rule defined by "old_range" to another 1D interval defined by "new_range" and scales the weights accordingly. More...
virtual bool	shapes_need_reinit ()

Static Public Member Functions
static std::unique_ptr< QBase >	build (const std::string &name, const unsigned int dim, const Order order=INVALID_ORDER)
	Builds a specific quadrature rule based on the name string. More...
static std::unique_ptr< QBase >	build (const QuadratureType qt, const unsigned int dim, const Order order=INVALID_ORDER)
	Builds a specific quadrature rule based on the QuadratureType. More...
static void	print_info (std::ostream &out=libMesh::out)
	Prints the reference information, by default to libMesh::out. More...
static std::string	get_info ()
	Gets a string containing the reference information. More...
static unsigned int	n_objects ()
	Prints the number of outstanding (created, but not yet destroyed) objects. More...
static void	enable_print_counter_info ()
	Methods to enable/disable the reference counter output from print_info() More...
static void	disable_print_counter_info ()

Public Attributes
bool	allow_rules_with_negative_weights
	Flag (default true) controlling the use of quadrature rules with negative weights. More...

Protected Types
typedef std::map< std::string, std::pair< unsigned int, unsigned int > >	Counts
	Data structure to log the information. More...

Protected Member Functions
virtual void	init_0D (const ElemType type=INVALID_ELEM, unsigned int p_level=0)
	Initializes the 0D quadrature rule by filling the points and weights vectors with the appropriate values. More...
void	tensor_product_quad (const QBase &q1D)
	Constructs a 2D rule from the tensor product of q1D with itself. More...
void	tensor_product_hex (const QBase &q1D)
	Computes the tensor product quadrature rule [q1D x q1D x q1D] from the 1D rule q1D. More...
void	tensor_product_prism (const QBase &q1D, const QBase &q2D)
	Computes the tensor product of a 1D quadrature rule and a 2D quadrature rule. More...
void	increment_constructor_count (const std::string &name)
	Increments the construction counter. More...
void	increment_destructor_count (const std::string &name)
	Increments the destruction counter. More...

Protected Attributes
unsigned int	_dim
	The spatial dimension of the quadrature rule. More...
Order	_order
	The polynomial order which the quadrature rule is capable of integrating exactly. More...
ElemType	_type
	The type of element for which the current values have been computed. More...
unsigned int	_p_level
	The p-level of the element for which the current values have been computed. More...
std::vector< Point >	_points
	The locations of the quadrature points in reference element space. More...
std::vector< Real >	_weights
	The quadrature weights. More...

Static Protected Attributes
static Counts	_counts
	Actually holds the data. More...
static Threads::atomic< unsigned int >	_n_objects
	The number of objects. More...
static Threads::spin_mutex	_mutex
	Mutual exclusion object to enable thread-safe reference counting. More...
static bool	_enable_print_counter
	Flag to control whether reference count information is printed when print_info is called. More...

Private Member Functions
virtual void	init_1D (const ElemType _type=INVALID_ELEM, unsigned int p_level=0) override
	Initializes the 1D quadrature rule by filling the points and weights vectors with the appropriate values. More...
virtual void	init_2D (const ElemType _type=INVALID_ELEM, unsigned int p_level=0) override
	Initializes the 2D quadrature rule by filling the points and weights vectors with the appropriate values. More...
virtual void	init_3D (const ElemType _type=INVALID_ELEM, unsigned int p_level=0) override
	Initializes the 3D quadrature rule by filling the points and weights vectors with the appropriate values. More...
void	dunavant_rule (const Real rule_data[][4], const unsigned int n_pts)
	The Dunavant rules are for triangles. More...
void	dunavant_rule2 (const Real *wts, const Real *a, const Real *b, const unsigned int *permutation_ids, const unsigned int n_wts)
void	keast_rule (const Real rule_data[][4], const unsigned int n_pts)
	The Keast rules are for tets. More...

Detailed Description

This class implements specific orders of Gauss quadrature.

The rules of Order p are capable of integrating polynomials of degree p exactly.

Author

Benjamin Kirk

John W. Peterson

Date

2003 Implements 1, 2, and 3D "Gaussian" quadrature rules.

Definition at line 39 of file quadrature_gauss.h.

Member Typedef Documentation

Counts

typedef std::map<std::string, std::pair<unsigned int, unsigned int> > libMesh::ReferenceCounter::Counts

protectedinherited

Data structure to log the information.

The log is identified by the class name.

Definition at line 117 of file reference_counter.h.

Constructor & Destructor Documentation

QGauss() [1/3]

libMesh::QGauss::QGauss	(	unsigned int	dim,
		Order	order = INVALID_ORDER
	)

Constructor.

Declares the order of the quadrature rule. We explicitly call the init function in 1D since the other tensor-product rules require this one.

Note

The element type, EDGE2, will not be used internally, however if we called the function with INVALID_ELEM it would try to be smart and return, thinking it had already done the work.

Definition at line 52 of file quadrature_gauss.h.

References libMesh::EDGE2, and libMesh::QBase::init().

                                     :
    QBase(dim, order)
  {
    if (dim == 1)
      init(EDGE2);
  }

QGauss() [2/3]

libMesh::QGauss::QGauss ( const QGauss &  )

default

Copy/move ctor, copy/move assignment operator, and destructor are all explicitly defaulted for this simple class.

QGauss() [3/3]

libMesh::QGauss::QGauss ( QGauss &&  )

default

~QGauss()

virtual libMesh::QGauss::~QGauss ( )

virtualdefault

Member Function Documentation

build() [1/2]

static std::unique_ptr<QBase> libMesh::QBase::build ( const std::string &  name, const unsigned int  dim, const Order  order = INVALID_ORDER  )

staticinherited

Builds a specific quadrature rule based on the name string.

This enables selection of the quadrature rule at run-time. The input parameter name must be mappable through the Utility::string_to_enum<>() function.

This function allocates memory, therefore a std::unique_ptr<QBase> is returned so that the user does not accidentally leak it.

build() [2/2]

static std::unique_ptr<QBase> libMesh::QBase::build ( const QuadratureType  qt, const unsigned int  dim, const Order  order = INVALID_ORDER  )

staticinherited

Builds a specific quadrature rule based on the QuadratureType.

This enables selection of the quadrature rule at run-time.

This function allocates memory, therefore a std::unique_ptr<QBase> is returned so that the user does not accidentally leak it.

disable_print_counter_info()

static void libMesh::ReferenceCounter::disable_print_counter_info ( )

staticinherited

dunavant_rule()

void libMesh::QGauss::dunavant_rule ( const Real  rule_data[][4], const unsigned int  n_pts  )

private

The Dunavant rules are for triangles.

This function takes permutation points and weights in a specific format as input and fills the _points and _weights vectors.

dunavant_rule2()

void libMesh::QGauss::dunavant_rule2 ( const Real *  wts, const Real *  a, const Real *  b, const unsigned int *  permutation_ids, const unsigned int  n_wts  )

private

enable_print_counter_info()

static void libMesh::ReferenceCounter::enable_print_counter_info ( )

staticinherited

Methods to enable/disable the reference counter output from print_info()

get_dim()

unsigned int libMesh::QBase::get_dim ( ) const

inherited

Returns

The spatial dimension of the quadrature rule.

Definition at line 136 of file quadrature.h.

References libMesh::QBase::_dim.

{ return _dim; }

get_elem_type()

ElemType libMesh::QBase::get_elem_type ( ) const

inherited

Returns

The element type we're currently using.

Definition at line 117 of file quadrature.h.

References libMesh::QBase::_type.

{ return _type; }

get_info()

static std::string libMesh::ReferenceCounter::get_info ( )

staticinherited

Gets a string containing the reference information.

get_order()

Order libMesh::QBase::get_order ( ) const

inherited

Returns

The order of the quadrature rule.

Definition at line 203 of file quadrature.h.

References libMesh::QBase::_order, and libMesh::QBase::_p_level.

{ return static_cast<Order>(_order + _p_level); }

get_p_level()

unsigned int libMesh::QBase::get_p_level ( ) const

inherited

Returns

The p-refinement level we're currently using.

Definition at line 122 of file quadrature.h.

References libMesh::QBase::_p_level.

{ return _p_level; }

get_points() [1/2]

const std::vector<Point>& libMesh::QBase::get_points ( ) const

inherited

Returns

A std::vector containing the quadrature point locations in reference element space.

Definition at line 142 of file quadrature.h.

References libMesh::QBase::_points.

Referenced by EIM_F::interior_assembly(), and AssemblyEIM::interior_assembly().

{ return _points; }

get_points() [2/2]

std::vector<Point>& libMesh::QBase::get_points ( )

inherited

Returns

A std::vector containing the quadrature point locations in reference element space as a writable reference.

Definition at line 148 of file quadrature.h.

References libMesh::QBase::_points.

{ return _points; }

get_weights() [1/2]

const std::vector<Real>& libMesh::QBase::get_weights ( ) const

inherited

Returns

A constant reference to a std::vector containing the quadrature weights.

Definition at line 154 of file quadrature.h.

References libMesh::QBase::_weights.

{ return _weights; }

get_weights() [2/2]

std::vector<Real>& libMesh::QBase::get_weights ( )

inherited

Returns

A writable references to a std::vector containing the quadrature weights.

Definition at line 160 of file quadrature.h.

References libMesh::QBase::_weights.

{ return _weights; }

increment_constructor_count()

void libMesh::ReferenceCounter::increment_constructor_count ( const std::string &  name )

protectedinherited

Increments the construction counter.

Should be called in the constructor of any derived class that will be reference counted.

Definition at line 181 of file reference_counter.h.

References libMesh::ReferenceCounter::_counts, libMesh::Quality::name(), and libMesh::Threads::spin_mtx.

Referenced by libMesh::ReferenceCountedObject< RBParametrized >::ReferenceCountedObject().

{
  Threads::spin_mutex::scoped_lock lock(Threads::spin_mtx);
  std::pair<unsigned int, unsigned int> & p = _counts[name];

  p.first++;
}

increment_destructor_count()

void libMesh::ReferenceCounter::increment_destructor_count ( const std::string &  name )

protectedinherited

Increments the destruction counter.

Should be called in the destructor of any derived class that will be reference counted.

Definition at line 194 of file reference_counter.h.

References libMesh::ReferenceCounter::_counts, libMesh::Quality::name(), and libMesh::Threads::spin_mtx.

Referenced by libMesh::ReferenceCountedObject< RBParametrized >::~ReferenceCountedObject().

{
  Threads::spin_mutex::scoped_lock lock(Threads::spin_mtx);
  std::pair<unsigned int, unsigned int> & p = _counts[name];

  p.second++;
}

init() [1/2]

virtual void libMesh::QBase::init ( const ElemType  type = INVALID_ELEM, unsigned int  p_level = 0  )

virtualinherited

Initializes the data structures for a quadrature rule for an element of type type.

Referenced by QGauss(), libMesh::QJacobi::QJacobi(), libMesh::QSimpson::QSimpson(), and libMesh::QTrap::QTrap().

init() [2/2]

virtual void libMesh::QBase::init ( const Elem &  elem, const std::vector< Real > &  vertex_distance_func, unsigned int  p_level = 0  )

virtualinherited

Initializes the data structures for an element potentially "cut" by a signed distance function.

The array vertex_distance_func contains vertex values of the signed distance function. If the signed distance function changes sign on the vertices, then the element is considered to be cut.) This interface can be extended by derived classes in order to subdivide the element and construct a composite quadrature rule.

init_0D()

virtual void libMesh::QBase::init_0D ( const ElemType  type = INVALID_ELEM, unsigned int  p_level = 0  )

protectedvirtualinherited

Initializes the 0D quadrature rule by filling the points and weights vectors with the appropriate values.

Generally this is just one point with weight 1.

init_1D()

virtual void libMesh::QGauss::init_1D ( const ElemType  type = INVALID_ELEM, unsigned int  p_level = 0  )

overrideprivatevirtual

Initializes the 1D quadrature rule by filling the points and weights vectors with the appropriate values.

The order of the rule will be defined by the implementing class. It is assumed that derived quadrature rules will at least define the init_1D function, therefore it is pure virtual.

Implements libMesh::QBase.

init_2D()

virtual void libMesh::QGauss::init_2D ( const ElemType  = INVALID_ELEM, unsigned int  = 0  )

overrideprivatevirtual

Initializes the 2D quadrature rule by filling the points and weights vectors with the appropriate values.

The order of the rule will be defined by the implementing class. Should not be pure virtual since a derived quadrature rule may only be defined in 1D. If not redefined, gives an error (when DEBUG is defined) when called.

Reimplemented from libMesh::QBase.

init_3D()

virtual void libMesh::QGauss::init_3D ( const ElemType  = INVALID_ELEM, unsigned int  = 0  )

overrideprivatevirtual

Initializes the 3D quadrature rule by filling the points and weights vectors with the appropriate values.

The order of the rule will be defined by the implementing class. Should not be pure virtual since a derived quadrature rule may only be defined in 1D. If not redefined, gives an error (when DEBUG is defined) when called.

Reimplemented from libMesh::QBase.

keast_rule()

void libMesh::QGauss::keast_rule ( const Real  rule_data[][4], const unsigned int  n_pts  )

private

The Keast rules are for tets.

This function takes permutation points and weights in a specific format as input and fills the _points and _weights vectors.

n_objects()

static unsigned int libMesh::ReferenceCounter::n_objects ( )

staticinherited

Prints the number of outstanding (created, but not yet destroyed) objects.

Definition at line 83 of file reference_counter.h.

References libMesh::ReferenceCounter::_n_objects.

  { return _n_objects; }

n_points()

unsigned int libMesh::QBase::n_points ( ) const

inherited

Returns

The number of points associated with the quadrature rule.

Definition at line 127 of file quadrature.h.

References libMesh::QBase::_points.

Referenced by AssemblyA0::boundary_assembly(), AssemblyA1::boundary_assembly(), A2::boundary_assembly(), AssemblyA2::boundary_assembly(), A3::boundary_assembly(), F0::boundary_assembly(), Output0::boundary_assembly(), SecondOrderScalarSystemSecondOrderTimeSolverBase::damping_residual(), SecondOrderScalarSystemFirstOrderTimeSolverBase::damping_residual(), FirstOrderScalarSystemBase::element_time_derivative(), SecondOrderScalarSystemFirstOrderTimeSolverBase::element_time_derivative(), A0::interior_assembly(), B::interior_assembly(), M0::interior_assembly(), A1::interior_assembly(), EIM_IP_assembly::interior_assembly(), AcousticsInnerProduct::interior_assembly(), A2::interior_assembly(), EIM_F::interior_assembly(), F0::interior_assembly(), OutputAssembly::interior_assembly(), AssemblyEIM::interior_assembly(), AssemblyF0::interior_assembly(), AssemblyF1::interior_assembly(), Ex6InnerProduct::interior_assembly(), Ex6EIMInnerProduct::interior_assembly(), FirstOrderScalarSystemBase::mass_residual(), SecondOrderScalarSystemSecondOrderTimeSolverBase::mass_residual(), SecondOrderScalarSystemFirstOrderTimeSolverBase::mass_residual(), and libMesh::QBase::print_info().

  {
    libmesh_assert (!_points.empty());
    return cast_int<unsigned int>(_points.size());
  }

operator=() [1/2]

QGauss& libMesh::QGauss::operator= ( const QGauss &  )

default

operator=() [2/2]

QGauss& libMesh::QGauss::operator= ( QGauss &&  )

default

print_info() [1/2]

static void libMesh::ReferenceCounter::print_info ( std::ostream &  out = libMesh::out )

staticinherited

Prints the reference information, by default to libMesh::out.

print_info() [2/2]

void libMesh::QBase::print_info ( std::ostream &  os = libMesh::out ) const

inherited

Prints information relevant to the quadrature rule, by default to libMesh::out.

Definition at line 378 of file quadrature.h.

References libMesh::QBase::_points, libMesh::QBase::_weights, libMesh::QBase::n_points(), and libMesh::Real.

{
  libmesh_assert(!_points.empty());
  libmesh_assert(!_weights.empty());

  Real summed_weights=0;
  os << "N_Q_Points=" << this->n_points() << std::endl << std::endl;
  for (unsigned int qpoint=0; qpoint<this->n_points(); qpoint++)
    {
      os << " Point " << qpoint << ":\n"
         << "  "
         << _points[qpoint]
         << "\n Weight:\n "
         << "  w=" << _weights[qpoint] << "\n" << std::endl;

      summed_weights += _weights[qpoint];
    }
  os << "Summed Weights: " << summed_weights << std::endl;
}

qp()

Point libMesh::QBase::qp ( const unsigned int  i ) const

inherited

Returns

The quadrature point in reference element space.

Definition at line 165 of file quadrature.h.

References libMesh::QBase::_points.

  {
    libmesh_assert_less (i, _points.size());
    return _points[i];
  }

scale()

void libMesh::QBase::scale ( std::pair< Real, Real >  old_range, std::pair< Real, Real >  new_range  )

inherited

Maps the points of a 1D quadrature rule defined by "old_range" to another 1D interval defined by "new_range" and scales the weights accordingly.

shapes_need_reinit()

virtual bool libMesh::QBase::shapes_need_reinit ( )

virtualinherited

Returns

true if the shape functions need to be recalculated, false otherwise.

This may be required if the number of quadrature points or their position changes.

Definition at line 231 of file quadrature.h.

{ return false; }

tensor_product_hex()

void libMesh::QBase::tensor_product_hex ( const QBase &  q1D )

protectedinherited

Computes the tensor product quadrature rule [q1D x q1D x q1D] from the 1D rule q1D.

Used in the init_3D routines for hexahedral element types.

tensor_product_prism()

void libMesh::QBase::tensor_product_prism ( const QBase &  q1D, const QBase &  q2D  )

protectedinherited

Computes the tensor product of a 1D quadrature rule and a 2D quadrature rule.

Used in the init_3D routines for prismatic element types.

tensor_product_quad()

void libMesh::QBase::tensor_product_quad ( const QBase &  q1D )

protectedinherited

Constructs a 2D rule from the tensor product of q1D with itself.

Used in the init_2D() routines for quadrilateral element types.

type()

virtual QuadratureType libMesh::QGauss::type ( ) const

overridevirtual

Returns

QGAUSS.

Implements libMesh::QBase.

w()

Real libMesh::QBase::w ( const unsigned int  i ) const

inherited

Returns

The quadrature weight.

Definition at line 174 of file quadrature.h.

References libMesh::QBase::_weights.

  {
    libmesh_assert_less (i, _weights.size());
    return _weights[i];
  }

Member Data Documentation

_counts

Counts libMesh::ReferenceCounter::_counts

staticprotectedinherited

Actually holds the data.

Definition at line 122 of file reference_counter.h.

Referenced by libMesh::ReferenceCounter::increment_constructor_count(), and libMesh::ReferenceCounter::increment_destructor_count().

_dim

unsigned int libMesh::QBase::_dim

protectedinherited

The spatial dimension of the quadrature rule.

Definition at line 325 of file quadrature.h.

Referenced by libMesh::QBase::get_dim(), libMesh::QJacobi::QJacobi(), libMesh::QSimpson::QSimpson(), and libMesh::QTrap::QTrap().

_enable_print_counter

bool libMesh::ReferenceCounter::_enable_print_counter

staticprotectedinherited

Flag to control whether reference count information is printed when print_info is called.

Definition at line 141 of file reference_counter.h.

_mutex

Threads::spin_mutex libMesh::ReferenceCounter::_mutex

staticprotectedinherited

Mutual exclusion object to enable thread-safe reference counting.

Definition at line 135 of file reference_counter.h.

_n_objects

Threads::atomic<unsigned int> libMesh::ReferenceCounter::_n_objects

staticprotectedinherited

The number of objects.

Print the reference count information when the number returns to 0.

Definition at line 130 of file reference_counter.h.

Referenced by libMesh::ReferenceCounter::n_objects(), libMesh::ReferenceCounter::ReferenceCounter(), and libMesh::ReferenceCounter::~ReferenceCounter().

_order

Order libMesh::QBase::_order

protectedinherited

The polynomial order which the quadrature rule is capable of integrating exactly.

Definition at line 331 of file quadrature.h.

Referenced by libMesh::QBase::get_order().

_p_level

unsigned int libMesh::QBase::_p_level

protectedinherited

The p-level of the element for which the current values have been computed.

Definition at line 343 of file quadrature.h.

Referenced by libMesh::QBase::get_order(), and libMesh::QBase::get_p_level().

_points

std::vector<Point> libMesh::QBase::_points

protectedinherited

The locations of the quadrature points in reference element space.

Definition at line 349 of file quadrature.h.

Referenced by libMesh::QBase::get_points(), libMesh::QBase::n_points(), libMesh::QBase::print_info(), and libMesh::QBase::qp().

_type

ElemType libMesh::QBase::_type

protectedinherited

The type of element for which the current values have been computed.

Definition at line 337 of file quadrature.h.

Referenced by libMesh::QBase::get_elem_type().

_weights

std::vector<Real> libMesh::QBase::_weights

protectedinherited

The quadrature weights.

The order of the weights matches the ordering of the _points vector.

Definition at line 355 of file quadrature.h.

Referenced by libMesh::QBase::get_weights(), libMesh::QBase::print_info(), and libMesh::QBase::w().

allow_rules_with_negative_weights

bool libMesh::QBase::allow_rules_with_negative_weights

inherited

Flag (default true) controlling the use of quadrature rules with negative weights.

Set this to false to require rules with all positive weights.

Rules with negative weights can be unsuitable for some problems. For example, it is possible for a rule with negative weights to obtain a negative result when integrating a positive function.

A particular example: if rules with negative weights are not allowed, a request for TET,THIRD (5 points) will return the TET,FIFTH (14 points) rule instead, nearly tripling the computational effort required!

Definition at line 246 of file quadrature.h.

---

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

• include/quadrature/quadrature_gauss.h