Delta function coefficient optionally multiplied by a weight coefficient and a scaled time dependent C-function. More...

#include <coefficient.hpp>

Inheritance diagram for mfem::DeltaCoefficient:

[legend]

Collaboration diagram for mfem::DeltaCoefficient:

[legend]

Public Member Functions
	DeltaCoefficient ()
	Construct a unit delta function centered at (0.0,0.0,0.0)

	DeltaCoefficient (real_t x, real_t s)
	Construct a delta function scaled by s and centered at (x,0.0,0.0)

	DeltaCoefficient (real_t x, real_t y, real_t s)
	Construct a delta function scaled by s and centered at (x,y,0.0)

	DeltaCoefficient (real_t x, real_t y, real_t z, real_t s)
	Construct a delta function scaled by s and centered at (x,y,z)

void	SetTime (real_t t) override
	Set the time for internally stored coefficients.

void	SetDeltaCenter (const Vector &center)
	Set the center location of the delta function.

void	SetScale (real_t s_)
	Set the scale value multiplying the delta function.

void	SetFunction (real_t(*f)(real_t))
	Set a time-dependent function that multiplies the Scale().

void	SetTol (real_t tol_)
	Set the tolerance used during projection onto GridFunction to identify the Mesh vertex where the Center() of the delta function lies. (default 1e-12)

void	SetWeight (Coefficient *w)
	Set a weight Coefficient that multiplies the DeltaCoefficient.

const real_t *	Center ()

real_t	Scale ()
	Return the scale factor times the optional time dependent function. Returns \( s T(t) \) with \( T(t) = 1 \) when not set by the user.

real_t	Tol ()
	Return the tolerance used to identify the mesh vertices.

Coefficient *	Weight ()
	See SetWeight() for description of the weight Coefficient.

void	GetDeltaCenter (Vector &center)
	Write the center of the delta function into center.

virtual real_t	EvalDelta (ElementTransformation &T, const IntegrationPoint &ip)
	The value of the function assuming we are evaluating at the delta center.

real_t	Eval (ElementTransformation &T, const IntegrationPoint &ip) override
	A DeltaFunction cannot be evaluated. Calling this method will cause an MFEM error, terminating the application.

virtual	~DeltaCoefficient ()

Public Member Functions inherited from mfem::Coefficient
	Coefficient ()

real_t	GetTime ()
	Get the time for time dependent coefficients.

int	GetVDim ()
	Returns dimension of the vector.

real_t	Eval (ElementTransformation &T, const IntegrationPoint &ip, real_t t)
	Evaluate the coefficient in the element described by T at the point ip at time t.

virtual void	Project (QuadratureFunction &qf)
	Fill the QuadratureFunction qf by evaluating the coefficient at the quadrature points.

virtual	~Coefficient ()

Protected Attributes
real_t	center [3]

real_t	scale

real_t	tol

Coefficient *	weight

int	sdim

real_t(*	tdf )(real_t)

Protected Attributes inherited from mfem::Coefficient
real_t	time

Detailed Description

Delta function coefficient optionally multiplied by a weight coefficient and a scaled time dependent C-function.

\( F(x,t) = w(x,t) s T(t) d(x - xc) \)

where w is the optional weight coefficient, s is a scale factor T is an optional time-dependent function and d is a delta function.

WARNING this cannot be used as a normal coefficient. The usual Eval method is disabled.

Definition at line 462 of file coefficient.hpp.

Constructor & Destructor Documentation

◆ DeltaCoefficient() [1/4]

mfem::DeltaCoefficient::DeltaCoefficient ( )

inline

Construct a unit delta function centered at (0.0,0.0,0.0)

Definition at line 473 of file coefficient.hpp.

◆ DeltaCoefficient() [2/4]

mfem::DeltaCoefficient::DeltaCoefficient	(	real_t	x,
		real_t	s )

inline

Construct a delta function scaled by s and centered at (x,0.0,0.0)

Definition at line 480 of file coefficient.hpp.

◆ DeltaCoefficient() [3/4]

mfem::DeltaCoefficient::DeltaCoefficient	(	real_t	x,
		real_t	y,
		real_t	s )

inline

Construct a delta function scaled by s and centered at (x,y,0.0)

Definition at line 487 of file coefficient.hpp.

◆ DeltaCoefficient() [4/4]

mfem::DeltaCoefficient::DeltaCoefficient	(	real_t	x,
		real_t	y,
		real_t	z,
		real_t	s )

inline

Construct a delta function scaled by s and centered at (x,y,z)

Definition at line 494 of file coefficient.hpp.

◆ ~DeltaCoefficient()

virtual mfem::DeltaCoefficient::~DeltaCoefficient ( )

inlinevirtual

Definition at line 549 of file coefficient.hpp.

Member Function Documentation

◆ Center()

const real_t * mfem::DeltaCoefficient::Center ( )

inline

Return a pointer to a c-array representing the center of the delta function.

Definition at line 527 of file coefficient.hpp.

◆ Eval()

real_t mfem::DeltaCoefficient::Eval	(	ElementTransformation &	T,
		const IntegrationPoint &	ip )

inlineoverridevirtual

A DeltaFunction cannot be evaluated. Calling this method will cause an MFEM error, terminating the application.

Implements mfem::Coefficient.

Definition at line 547 of file coefficient.hpp.

◆ EvalDelta()

real_t mfem::DeltaCoefficient::EvalDelta	(	ElementTransformation &	T,
		const IntegrationPoint &	ip )

virtual

The value of the function assuming we are evaluating at the delta center.

Definition at line 298 of file coefficient.cpp.

◆ GetDeltaCenter()

void mfem::DeltaCoefficient::GetDeltaCenter ( Vector & center )

Write the center of the delta function into center.

Definition at line 292 of file coefficient.cpp.

◆ Scale()

real_t mfem::DeltaCoefficient::Scale ( )

inline

Return the scale factor times the optional time dependent function. Returns \( s T(t) \) with \( T(t) = 1 \) when not set by the user.

Definition at line 532 of file coefficient.hpp.

◆ SetDeltaCenter()

void mfem::DeltaCoefficient::SetDeltaCenter ( const Vector & center )

Set the center location of the delta function.

Definition at line 284 of file coefficient.cpp.

◆ SetFunction()

void mfem::DeltaCoefficient::SetFunction ( real_t(* f )(real_t) )

inline

Set a time-dependent function that multiplies the Scale().

Definition at line 510 of file coefficient.hpp.

◆ SetScale()

void mfem::DeltaCoefficient::SetScale ( real_t s_ )

inline

Set the scale value multiplying the delta function.

Definition at line 507 of file coefficient.hpp.

◆ SetTime()

void mfem::DeltaCoefficient::SetTime ( real_t t )

overridevirtual

Set the time for internally stored coefficients.

Reimplemented from mfem::Coefficient.

Definition at line 278 of file coefficient.cpp.

◆ SetTol()

void mfem::DeltaCoefficient::SetTol ( real_t tol_ )

inline

Set the tolerance used during projection onto GridFunction to identify the Mesh vertex where the Center() of the delta function lies. (default 1e-12)

Definition at line 515 of file coefficient.hpp.

◆ SetWeight()

void mfem::DeltaCoefficient::SetWeight ( Coefficient * w )

inline

Set a weight Coefficient that multiplies the DeltaCoefficient.

The weight Coefficient multiplies the value returned by EvalDelta() but not the value returned by Scale(). The weight Coefficient is also used as the L2-weight function when projecting the DeltaCoefficient onto a GridFunction, so that the weighted integral of the projection is exactly equal to the Scale().

Definition at line 523 of file coefficient.hpp.

◆ Tol()

real_t mfem::DeltaCoefficient::Tol ( )

inline

Return the tolerance used to identify the mesh vertices.

Definition at line 535 of file coefficient.hpp.

◆ Weight()

Coefficient * mfem::DeltaCoefficient::Weight ( )

inline

See SetWeight() for description of the weight Coefficient.

Definition at line 538 of file coefficient.hpp.

Member Data Documentation

◆ center

real_t mfem::DeltaCoefficient::center[3]

protected

Definition at line 465 of file coefficient.hpp.

◆ scale

real_t mfem::DeltaCoefficient::scale

protected

Definition at line 465 of file coefficient.hpp.

◆ sdim

int mfem::DeltaCoefficient::sdim

protected

Definition at line 467 of file coefficient.hpp.

◆ tdf

real_t(* mfem::DeltaCoefficient::tdf) (real_t)

protected

Definition at line 468 of file coefficient.hpp.

◆ tol

real_t mfem::DeltaCoefficient::tol

protected

Definition at line 465 of file coefficient.hpp.

◆ weight

Coefficient* mfem::DeltaCoefficient::weight

protected

Definition at line 466 of file coefficient.hpp.

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

fem/coefficient.hpp
fem/coefficient.cpp

Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ DeltaCoefficient() [1/4]

◆ DeltaCoefficient() [2/4]

◆ DeltaCoefficient() [3/4]

◆ DeltaCoefficient() [4/4]

◆ ~DeltaCoefficient()

Member Function Documentation

◆ Center()

◆ Eval()

◆ EvalDelta()

◆ GetDeltaCenter()

◆ Scale()

◆ SetDeltaCenter()

◆ SetFunction()

◆ SetScale()

◆ SetTime()

◆ SetTol()

◆ SetWeight()

◆ Tol()

◆ Weight()

Member Data Documentation

◆ center

◆ scale

◆ sdim

◆ tdf

◆ tol

◆ weight