getfem::mesh_fem Class Reference

Describe a finite element method linked to a mesh. More...

#include <getfem_mesh_fem.h>

Inherits getfem::context_dependencies, and dal::static_stored_object.

Inherited by getfem::mesh_fem_global_function, getfem::mesh_fem_level_set, getfem::mesh_fem_product, getfem::mesh_fem_sum, getfem::partial_mesh_fem, and getfem::torus_mesh_fem.

Public Member Functions
void	update_from_context () const
	this function has to be defined and should update the object when the context is modified.
const dal::bit_vector &	convex_index () const
	Get the set of convexes where a finite element has been assigned.
bool	is_reduced () const
	Return true if a reduction matrix is applied to the dofs.
const REDUCTION_MATRIX &	reduction_matrix () const
	Return the reduction matrix applied to the dofs.
const EXTENSION_MATRIX &	extension_matrix () const
	Return the extension matrix corresponding to reduction applied (RE=I).
template<typename MATR , typename MATE >
void	set_reduction_matrices (const MATR &RR, const MATE &EE)
	Allows to set the reduction and the extension matrices. More...
void	reduce_to_basic_dof (const dal::bit_vector &kept_basic_dof)
	Allows to set the reduction and the extension matrices in order to keep only a certain number of dof.
void	set_reduction (bool r)
	Validate or invalidate the reduction (keeping the reduction matrices).
const mesh &	linked_mesh () const
	Return a reference to the underlying mesh.
void	set_auto_add (dim_type K, bool disc=false, scalar_type alpha=scalar_type(0), bool complete=false)
	Set the degree of the fem for automatic addition of element option. More...
void	set_auto_add (pfem pf)
	Set the fem for automatic addition of element option. More...
virtual dim_type	get_qdim () const
	Return the Q dimension. More...
virtual void	set_qdim (dim_type q)
	Change the Q dimension.
virtual void	set_qdim (dim_type M, dim_type N)
	Set the dimension for a matrix field.
virtual void	set_qdim (dim_type M, dim_type N, dim_type O, dim_type P)
	Set the dimension for a fourth order tensor field.
virtual void	set_qdim (const bgeot::multi_index &mii)
	Set the dimension for an arbitrary order tensor field.
dim_type	get_qdim_m () const IS_DEPRECATED
	for matrix fields, return the number of rows.
dim_type	get_qdim_n () const IS_DEPRECATED
	for matrix fields, return the number of columns.
void	set_finite_element (size_type cv, pfem pf)
	Set the finite element method of a convex. More...
void	set_finite_element (const dal::bit_vector &cvs, pfem pf)
	Set the finite element on a set of convexes. More...
void	set_finite_element (pfem pf)
	shortcut for set_finite_element(linked_mesh().convex_index(),pf); and set_auto_add(pf).
void	set_classical_finite_element (size_type cv, dim_type fem_degree, bool complete=false)
	Set a classical (i.e. More...
void	set_classical_finite_element (const dal::bit_vector &cvs, dim_type fem_degree, bool complete=false)
	Set a classical (i.e. More...
void	set_classical_discontinuous_finite_element (size_type cv, dim_type fem_degree, scalar_type alpha=0, bool complete=false)
	Similar to set_classical_finite_element, but uses discontinuous lagrange elements. More...
void	set_classical_discontinuous_finite_element (const dal::bit_vector &cvs, dim_type fem_degree, scalar_type alpha=0, bool complete=false)
	Similar to set_classical_finite_element, but uses discontinuous lagrange elements. More...
void	set_classical_finite_element (dim_type fem_degree, bool complete=false)
	Shortcut for set_classical_finite_element(linked_mesh().convex_index(),...)
void	set_classical_discontinuous_finite_element (dim_type fem_degree, scalar_type alpha=0, bool complete=false)
	Shortcut for set_classical_discontinuous_finite_element(linked_mesh().convex_index() ,...)
virtual pfem	fem_of_element (size_type cv) const
	Return the basic fem associated with an element (if no fem is associated, the function will crash! use the convex_index() of the mesh_fem to check that a fem is associated to a given convex). More...
virtual ind_dof_ct	ind_basic_dof_of_element (size_type cv) const
	Give an array of the dof numbers a of convex. More...
virtual ind_dof_face_ct	ind_basic_dof_of_face_of_element (size_type cv, short_type f) const
	Give an array of the dof numbers lying of a convex face (all degrees of freedom whose associated base function is non-zero on the convex face). More...
virtual size_type	nb_basic_dof_of_face_of_element (size_type cv, short_type f) const
	Return the number of dof lying on the given convex face. More...
virtual size_type	nb_basic_dof_of_element (size_type cv) const
	Return the number of degrees of freedom attached to a given convex. More...
virtual base_node	point_of_basic_dof (size_type cv, size_type i) const
	Return the geometrical location of a degree of freedom. More...
virtual base_node	point_of_basic_dof (size_type d) const
	Return the geometrical location of a degree of freedom. More...
virtual dim_type	basic_dof_qdim (size_type d) const
	Return the dof component number (0<= x <Qdim)
virtual size_type	first_convex_of_basic_dof (size_type d) const
	Shortcut for convex_to_dof(d)[0]. More...
virtual const mesh::ind_cv_ct &	convex_to_basic_dof (size_type d) const
	Return the list of convexes attached to the specified dof. More...
virtual void	get_global_dof_index (std::vector< size_type > &ind) const
	Give an array that contains the global dof indices corresponding to the mesh_fem dofs or size_type(-1) if a dof is not global. More...
virtual void	enumerate_dof () const
	Renumber the degrees of freedom. More...
virtual size_type	nb_basic_dof () const
	Return the total number of basic degrees of freedom (before the optional reduction).
virtual size_type	nb_dof () const
	Return the total number of degrees of freedom.
virtual dal::bit_vector	basic_dof_on_region (const mesh_region &b) const
	Get a list of basic dof lying on a given mesh_region. More...
dal::bit_vector	dof_on_region (const mesh_region &b) const
	Get a list of dof lying on a given mesh_region. More...
	mesh_fem (const mesh &me, dim_type Q=1)
	Build a new mesh_fem. More...
virtual void	read_from_file (std::istream &ist)
	Read the mesh_fem from a stream. More...
void	read_from_file (const std::string &name)
	Read the mesh_fem from a file. More...
virtual void	write_to_file (std::ostream &ost) const
	Write the mesh_fem to a stream.
void	write_to_file (const std::string &name, bool with_mesh=false) const
	Write the mesh_fem to a file. More...
Public Member Functions inherited from getfem::context_dependencies
bool	context_check () const
	return true if update_from_context was called

Detailed Description

Describe a finite element method linked to a mesh.

See also

mesh

mesh_im

Definition at line 152 of file getfem_mesh_fem.h.

Constructor & Destructor Documentation

mesh_fem()

getfem::mesh_fem::mesh_fem ( const mesh &  me, dim_type  Q = 1  )

explicit

Build a new mesh_fem.

A mesh object must be supplied.

Parameters

me	the linked mesh.
Q	the Q dimension (see mesh_fem::get_qdim).

Definition at line 527 of file getfem_mesh_fem.cc.

Member Function Documentation

set_reduction_matrices()

template<typename MATR , typename MATE >

void getfem::mesh_fem::set_reduction_matrices ( const MATR &  RR, const MATE &  EE  )

inline

Allows to set the reduction and the extension matrices.

Should satify (RR*EE=I).

Definition at line 210 of file getfem_mesh_fem.h.

set_auto_add() [1/2]

void getfem::mesh_fem::set_auto_add ( dim_type  K, bool  disc = false, scalar_type  alpha = scalar_type(0), bool  complete = false  )

inline

Set the degree of the fem for automatic addition of element option.

K=-1 disables the automatic addition.

Definition at line 291 of file getfem_mesh_fem.h.

set_auto_add() [2/2]

void getfem::mesh_fem::set_auto_add ( pfem  pf )

inline

Set the fem for automatic addition of element option.

pf=0 disables the automatic addition.

Definition at line 304 of file getfem_mesh_fem.h.

get_qdim()

virtual dim_type getfem::mesh_fem::get_qdim ( ) const

inlinevirtual

Return the Q dimension.

A mesh_fem used for scalar fields has Q=1, for vector fields, Q is typically equal to linked_mesh().dim().

Reimplemented in getfem::partial_mesh_fem.

Definition at line 316 of file getfem_mesh_fem.h.

set_finite_element() [1/2]

void getfem::mesh_fem::set_finite_element	(	size_type	cv,
		pfem	pf
	)

Set the finite element method of a convex.

Parameters

cv	the convex number.
pf	the finite element.

Definition at line 127 of file getfem_mesh_fem.cc.

set_finite_element() [2/2]

void getfem::mesh_fem::set_finite_element	(	const dal::bit_vector &	cvs,
		pfem	pf
	)

Set the finite element on a set of convexes.

Parameters

cvs	the set of convex indexes, as a dal::bit_vector.
pf	the finite element, typically obtained with getfem::fem_descriptor("FEM_SOMETHING(..)")

Definition at line 166 of file getfem_mesh_fem.cc.

set_classical_finite_element() [1/2]

void getfem::mesh_fem::set_classical_finite_element	(	size_type	cv,
		dim_type	fem_degree,
		bool	complete = false
	)

Set a classical (i.e.

lagrange polynomial) finite element on a convex.

Parameters

cv	is the convex number.
fem_degree	the polynomial degree of the finite element.
complete	is a flag for excluding incomplete element irrespective of the element geometric transformation.

Definition at line 174 of file getfem_mesh_fem.cc.

set_classical_finite_element() [2/2]

void getfem::mesh_fem::set_classical_finite_element	(	const dal::bit_vector &	cvs,
		dim_type	fem_degree,
		bool	complete = false
	)

Set a classical (i.e.

lagrange polynomial) finite element on a set of convexes.

Parameters

cvs	the set of convexes, as a dal::bit_vector.
fem_degree	the polynomial degree of the finite element.

Definition at line 182 of file getfem_mesh_fem.cc.

set_classical_discontinuous_finite_element() [1/2]

void getfem::mesh_fem::set_classical_discontinuous_finite_element	(	size_type	cv,
		dim_type	fem_degree,
		scalar_type	alpha = 0,
		bool	complete = false
	)

Similar to set_classical_finite_element, but uses discontinuous lagrange elements.

Parameters

cv	the convex index.
fem_degree	the polynomial degree of the finite element.
alpha	the node inset, 0 <= alpha < 1, where 0 implies usual dof nodes, greater values move the nodes toward the center of gravity, and 1 means that all degrees of freedom collapse on the center of gravity.

Definition at line 199 of file getfem_mesh_fem.cc.

set_classical_discontinuous_finite_element() [2/2]

void getfem::mesh_fem::set_classical_discontinuous_finite_element	(	const dal::bit_vector &	cvs,
		dim_type	fem_degree,
		scalar_type	alpha = 0,
		bool	complete = false
	)

Similar to set_classical_finite_element, but uses discontinuous lagrange elements.

Parameters

cvs	the set of convexes, as a dal::bit_vector.
fem_degree	the polynomial degree of the finite element.
alpha	the node inset, 0 <= alpha < 1, where 0 implies usual dof nodes, greater values move the nodes toward the center of gravity, and 1 means that all degrees of freedom collapse on the center of gravity.

Definition at line 206 of file getfem_mesh_fem.cc.

fem_of_element()

virtual pfem getfem::mesh_fem::fem_of_element ( size_type  cv ) const

inlinevirtual

Return the basic fem associated with an element (if no fem is associated, the function will crash! use the convex_index() of the mesh_fem to check that a fem is associated to a given convex).

This fem does not take into account the optional vectorization due to qdim nor the optional reduction.

Reimplemented in getfem::partial_mesh_fem.

Definition at line 448 of file getfem_mesh_fem.h.

ind_basic_dof_of_element()

virtual ind_dof_ct getfem::mesh_fem::ind_basic_dof_of_element ( size_type  cv ) const

inlinevirtual

Give an array of the dof numbers a of convex.

Parameters

cv	the convex number.

Returns

a pseudo-container of the dof number.

Reimplemented in getfem::partial_mesh_fem.

Definition at line 454 of file getfem_mesh_fem.h.

ind_basic_dof_of_face_of_element()

virtual ind_dof_face_ct getfem::mesh_fem::ind_basic_dof_of_face_of_element ( size_type  cv, short_type  f  ) const

inlinevirtual

Give an array of the dof numbers lying of a convex face (all degrees of freedom whose associated base function is non-zero on the convex face).

Parameters

cv	the convex number.
f	the face number.

Returns

a pseudo-container of the dof number.

Reimplemented in getfem::partial_mesh_fem.

Definition at line 472 of file getfem_mesh_fem.h.

nb_basic_dof_of_face_of_element()

virtual size_type getfem::mesh_fem::nb_basic_dof_of_face_of_element ( size_type  cv, short_type  f  ) const

inlinevirtual

Return the number of dof lying on the given convex face.

Parameters

cv	the convex number.
f	the face number.

Reimplemented in getfem::partial_mesh_fem.

Definition at line 485 of file getfem_mesh_fem.h.

nb_basic_dof_of_element()

virtual size_type getfem::mesh_fem::nb_basic_dof_of_element ( size_type  cv ) const

inlinevirtual

Return the number of degrees of freedom attached to a given convex.

Parameters

cv	the convex number.

Reimplemented in getfem::partial_mesh_fem.

Definition at line 498 of file getfem_mesh_fem.h.

point_of_basic_dof() [1/2]

base_node getfem::mesh_fem::point_of_basic_dof ( size_type  cv, size_type  i  ) const

virtual

Return the geometrical location of a degree of freedom.

Parameters

cv	the convex number.
i	the local dof number.

Reimplemented in getfem::partial_mesh_fem.

Definition at line 223 of file getfem_mesh_fem.cc.

point_of_basic_dof() [2/2]

base_node getfem::mesh_fem::point_of_basic_dof ( size_type  d ) const

virtual

Return the geometrical location of a degree of freedom.

Parameters

d	the global dof number.

Reimplemented in getfem::partial_mesh_fem.

Definition at line 231 of file getfem_mesh_fem.cc.

first_convex_of_basic_dof()

size_type getfem::mesh_fem::first_convex_of_basic_dof ( size_type  d ) const

virtual

Shortcut for convex_to_dof(d)[0].

Parameters

d	the global dof number.

Reimplemented in getfem::partial_mesh_fem.

Definition at line 258 of file getfem_mesh_fem.cc.

convex_to_basic_dof()

const mesh::ind_cv_ct & getfem::mesh_fem::convex_to_basic_dof ( size_type  d ) const

virtual

Return the list of convexes attached to the specified dof.

Parameters

d	the global dof number.

Returns

an array of convex numbers.

Reimplemented in getfem::partial_mesh_fem.

Definition at line 267 of file getfem_mesh_fem.cc.

get_global_dof_index()

void getfem::mesh_fem::get_global_dof_index ( std::vector< size_type > &  ind ) const

virtual

Give an array that contains the global dof indices corresponding to the mesh_fem dofs or size_type(-1) if a dof is not global.

Parameters

ind	the returned global dof indices array.

Definition at line 293 of file getfem_mesh_fem.cc.

enumerate_dof()

void getfem::mesh_fem::enumerate_dof ( void  ) const

virtual

Renumber the degrees of freedom.

Enumeration of dofs.

You should not have to call this function, as it is done automatically

Reimplemented in getfem::torus_mesh_fem.

Definition at line 321 of file getfem_mesh_fem.cc.

basic_dof_on_region()

dal::bit_vector getfem::mesh_fem::basic_dof_on_region ( const mesh_region &  b ) const

virtual

Get a list of basic dof lying on a given mesh_region.

Parameters

b	the mesh_region.

Returns

the list in a dal::bit_vector.

Reimplemented in getfem::partial_mesh_fem.

Definition at line 77 of file getfem_mesh_fem.cc.

dof_on_region()

dal::bit_vector getfem::mesh_fem::dof_on_region

(

const mesh_region &

b

)

const

Get a list of dof lying on a given mesh_region.

For a reduced mesh_fem a dof is lying on a region if its potential corresponding shape function is nonzero on this region. The extension matrix is used to make the correspondence between basic and reduced dofs.

Parameters

b	the mesh_region.

Returns

the list in a dal::bit_vector.

Definition at line 114 of file getfem_mesh_fem.cc.

read_from_file() [1/2]

void getfem::mesh_fem::read_from_file ( std::istream &  ist )

virtual

Read the mesh_fem from a stream.

Parameters

ist	the stream.

Reimplemented in getfem::partial_mesh_fem.

Definition at line 539 of file getfem_mesh_fem.cc.

read_from_file() [2/2]

void getfem::mesh_fem::read_from_file

(

const std::string &

name

)

Read the mesh_fem from a file.

Parameters

name	the file name.

Definition at line 703 of file getfem_mesh_fem.cc.

write_to_file()

void getfem::mesh_fem::write_to_file	(	const std::string &	name,
		bool	with_mesh = false
	)		const

Write the mesh_fem to a file.

Parameters

name	the file name
with_mesh	if set, then the linked_mesh() will also be saved to the file.

Definition at line 785 of file getfem_mesh_fem.cc.

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

• src/getfem/getfem_mesh_fem.h
• src/getfem_mesh_fem.cc