A variable which is solved for in a System of equations. More...

#include <variable.h>

Inheritance diagram for libMesh::Variable:

Public Member Functions
	Variable (System *sys, const std::string &var_name, const unsigned int var_number, const unsigned int first_scalar_num, const FEType &var_type)

	Variable (System *sys, const std::string &var_name, const unsigned int var_number, const unsigned int first_scalar_num, const FEType &var_type, const std::set< subdomain_id_type > &var_active_subdomains)

System *	system () const

const std::string &	name () const

unsigned int	number () const

unsigned int	first_scalar_number () const

const FEType &	type () const

unsigned int	n_components () const

bool	active_on_subdomain (subdomain_id_type sid) const

bool	implicitly_active () const

const std::set< subdomain_id_type > &	active_subdomains () const

Protected Attributes
System *	_sys

std::string	_name

std::set< subdomain_id_type >	_active_subdomains

unsigned int	_number

unsigned int	_first_scalar_number

FEType	_type

Detailed Description

A variable which is solved for in a System of equations.

This class defines the notion of a variable in the system. A variable is one of potentially several unknowns in the problem at hand. A variable is described by a unique name, a finite element approximation family, and (optionally) a list of subdomains to which the variable is restricted.

Author: Roy Stogner

Date: 2010

Definition at line 49 of file variable.h.

Constructor & Destructor Documentation

◆ Variable() [1/2]

libMesh::Variable::Variable	(	System *	sys,
		const std::string &	var_name,
		const unsigned int	var_number,
		const unsigned int	first_scalar_num,
		const FEType &	var_type
	)

inline

Constructor. Omits the subdomain mapping, hence this constructor creates a variable which is active on all subdomains.

Definition at line 58 of file variable.h.

Referenced by libMesh::VariableGroup::variable().

                                      :
     _sys(sys),
     _name(var_name),
     _active_subdomains(),
     _number(var_number),
     _first_scalar_number(first_scalar_num),
     _type(var_type)
   {}

◆ Variable() [2/2]

libMesh::Variable::Variable	(	System *	sys,
		const std::string &	var_name,
		const unsigned int	var_number,
		const unsigned int	first_scalar_num,
		const FEType &	var_type,
		const std::set< subdomain_id_type > &	var_active_subdomains
	)

inline

Constructor. Takes a set which contains the subdomain indices for which this variable is active.

Definition at line 75 of file variable.h.

                                                                      :
     _sys(sys),
     _name(var_name),
     _active_subdomains(var_active_subdomains),
     _number(var_number),
     _first_scalar_number(first_scalar_num),
     _type(var_type)
   {}

Member Function Documentation

◆ active_on_subdomain()

bool libMesh::Variable::active_on_subdomain ( subdomain_id_type sid ) const

inline

Returns: true if this variable is active on subdomain sid, false otherwise.

Note: We interpret the special case of an empty _active_subdomains container as active everywhere, i.e. for all subdomains.

Definition at line 136 of file variable.h.

References _active_subdomains.

Referenced by libMesh::ExactSolution::_compute_error(), libMesh::DofMap::_dof_indices(), libMesh::EquationSystems::build_discontinuous_solution_vector(), libMesh::EquationSystems::build_parallel_elemental_solution_vector(), libMesh::EquationSystems::build_parallel_solution_vector(), libMesh::DofMap::distribute_local_dofs_node_major(), libMesh::DofMap::distribute_local_dofs_var_major(), libMesh::DofMap::dof_indices(), libMesh::DofMap::local_variable_indices(), libMesh::DofMap::old_dof_indices(), libMesh::GenericProjector< FFunctor, GFunctor, FValue, ProjectionAction >::operator()(), libMesh::BoundaryProjectSolution::operator()(), and libMesh::DofMap::reinit().

137 { return (_active_subdomains.empty() || _active_subdomains.count(sid)); }

libMesh::Variable::_active_subdomains

std::set< subdomain_id_type > _active_subdomains

Definition: variable.h:156

◆ active_subdomains()

const std::set<subdomain_id_type>& libMesh::Variable::active_subdomains ( ) const

inline

Returns: The set of subdomain ids this variable lives on.

Definition at line 150 of file variable.h.

References _active_subdomains.

Referenced by libMesh::DifferentiableSystem::add_second_order_dot_vars(), libMesh::EquationSystems::get_vars_active_subdomains(), libMesh::VariableGroup::variable(), and libMesh::System::write_header().

151 { return _active_subdomains; }

libMesh::Variable::_active_subdomains

std::set< subdomain_id_type > _active_subdomains

Definition: variable.h:156

◆ first_scalar_number()

unsigned int libMesh::Variable::first_scalar_number ( ) const

inline

Returns: The index of the first scalar component of this variable in the system.

Definition at line 113 of file variable.h.

References _first_scalar_number.

Referenced by libMesh::System::n_components(), and libMesh::VariableGroup::variable().

114 { return _first_scalar_number; }

libMesh::Variable::_first_scalar_number

unsigned int _first_scalar_number

Definition: variable.h:158

◆ implicitly_active()

bool libMesh::Variable::implicitly_active ( ) const

inline

Returns: true if this variable is active on all subdomains because it has no specified activity map. This can be used to perform more efficient computations in some places.

Definition at line 144 of file variable.h.

References _active_subdomains.

145 { return _active_subdomains.empty(); }

libMesh::Variable::_active_subdomains

std::set< subdomain_id_type > _active_subdomains

Definition: variable.h:156