MDE solver for one direction of one block. More...

#include <Propagator.h>

Inheritance diagram for Pscf::Rpc::Propagator< D >:

Public Types
typedef RField< D >	Field
	Generic field (function of position, defined on regular grid).

typedef RField< D >	WField
	Chemical potential field type (r-grid format)

typedef RField< D >	CField
	Monomer concentration field type (r-grid format)

typedef RField< D >	QField
	Propagator q-field type, i.e., q(r,s) at fixed s.

Public Member Functions
	Propagator ()
	Constructor.

	~Propagator ()
	Destructor.

void	setBlock (Block< D > &block)
	Associate this propagator with a unique block.

void	allocate (int ns, const Mesh< D > &mesh)
	Allocate memory used by this propagator.

void	reallocate (int ns)
	Reallocate memory used by this propagator.

void	solve ()
	Solve the modified diffusion equation (MDE) for this block.

void	solve (QField const &head)
	Solve the MDE for a specified initial condition.

double	computeQ ()
	Compute and return partition function for the polymer.

const QField &	q (int i) const
	Return q-field at specified step.

const QField &	head () const
	Return q-field at beginning of the block (initial condition).

const QField &	tail () const
	Return q-field at the end of the block.

Block< D > &	block ()
	Get the associated Block object by reference.

int	ns () const
	Number of values of s (or slices), including head and tail.

bool	isAllocated () const
	Has memory been allocated for this propagator?

Public Member Functions inherited from Pscf::PropagatorTmpl< Propagator< D > >
	PropagatorTmpl ()
	Constructor.

void	setDirectionId (int directionId)
	Associate this propagator with a direction index.

void	setPartner (const Propagator< D > &partner)
	Set the partner of this propagator.

void	addSource (const Propagator< D > &source)
	Add a propagator to the list of sources for this one.

void	setIsSolved (bool isSolved)
	Set the isSolved flag to true or false.

const Propagator< D > &	source (int id) const
	Get a source propagator.

const Propagator< D > &	partner () const
	Get partner propagator.

int	directionId () const
	Get direction index for this propagator.

int	nSource () const
	Number of source / prerequisite propagators.

bool	hasPartner () const
	Does this have a partner propagator?

bool	isSolved () const
	Has the modified diffusion equation been solved?

bool	isReady () const
	Are all source propagators solved?

Protected Member Functions
void	computeHead ()
	Compute initial QField at head from tail QFields of sources.

Detailed Description

template<int D>
class Pscf::Rpc::Propagator< D >

MDE solver for one direction of one block.

A fully initialized Propagator<D> has an association with a Block<D> that owns this propagator and its partner, and has an association with a Mesh<D> that describes a spatial grid, in addition to associations with partner and source Propagator<D> objects that are managed by the PropagatorTmpl base class template.

The associated Block<D> stores information required to numerically solve the modified diffusion equation (MDE), including the contour step size ds and all parameters that depend on ds. These quantities are set and stored by the block because their values must be the same for the two propagators owned by each block (i.e., this propagator and its partner). The algorithm used by a propagator to solve the the MDE simply repeatedly calls the step() function of the associated block, because that function has access to all the parameters used in the numerical solution.

Definition at line 49 of file rpc/solvers/Propagator.h.

Member Typedef Documentation

◆ Field

template<int D>

RField<D> Pscf::Rpc::Propagator< D >::Field

Generic field (function of position, defined on regular grid).

Definition at line 59 of file rpc/solvers/Propagator.h.

◆ WField

template<int D>

RField<D> Pscf::Rpc::Propagator< D >::WField

Chemical potential field type (r-grid format)

Definition at line 64 of file rpc/solvers/Propagator.h.

◆ CField

template<int D>

RField<D> Pscf::Rpc::Propagator< D >::CField

Monomer concentration field type (r-grid format)

Definition at line 69 of file rpc/solvers/Propagator.h.

◆ QField

template<int D>

RField<D> Pscf::Rpc::Propagator< D >::QField

Propagator q-field type, i.e., q(r,s) at fixed s.

Definition at line 74 of file rpc/solvers/Propagator.h.

Constructor & Destructor Documentation

◆ Propagator()

template<int D>

Pscf::Rpc::Propagator< D >::Propagator ( )

Constructor.

Definition at line 25 of file rpc/solvers/Propagator.tpp.

◆ ~Propagator()

template<int D>

Pscf::Rpc::Propagator< D >::~Propagator ( )

Destructor.

Definition at line 36 of file rpc/solvers/Propagator.tpp.

Member Function Documentation

◆ setBlock()

template<int D>

void Pscf::Rpc::Propagator< D >::setBlock ( Block< D > & block )

inline

Associate this propagator with a unique block.

Parameters

block associated Block object.

Definition at line 293 of file rpc/solvers/Propagator.h.

◆ allocate()

template<int D>

void Pscf::Rpc::Propagator< D >::allocate	(	int	ns,
		const Mesh< D > &	mesh )

Allocate memory used by this propagator.

The parameter ns is the number of values of s at which q(r,s) is calculated, including the end values at the terminating vertices. See docs for the function ns(), which returns this value.

The address of the associated Mesh<D> object is retained.

An Exception is thrown if the propagator is already allocated.

Parameters

ns	number of slices (including end points)
mesh	spatial discretization mesh

Definition at line 43 of file rpc/solvers/Propagator.tpp.

References Pscf::Mesh< D >::dimensions(), and UTIL_CHECK.

◆ reallocate()

template<int D>

void Pscf::Rpc::Propagator< D >::reallocate ( int ns )

Reallocate memory used by this propagator.

This function is used when the value of ns is changed after initial allocation. This occurs during parameter sweeps that change the block length. See the docs for the function ns() for the definition of ns.

The spatial mesh is set by derefencing a pointer to the associated Mesh<D> object, which was set by a previous call to allocate.

An Exception is thrown if the propagator has not been previously allocated, or if the parameter ns is equal to the current value.

Parameters

ns	number of slices (including end points)

Definition at line 60 of file rpc/solvers/Propagator.tpp.

References UTIL_CHECK.

◆ solve() [1/2]

template<int D>

void Pscf::Rpc::Propagator< D >::solve ( )

Solve the modified diffusion equation (MDE) for this block.

This function computes an initial QField at the head of this block, and then solves the modified diffusion equation (MDE) to propagate the solution from the head to the tail. The initial QField at the head is computed by pointwise multiplication of the tail QFields of all source propagators. The MDE is solved by repeatedly calling the step() function of the associated Block<D> .

Definition at line 119 of file rpc/solvers/Propagator.tpp.

References UTIL_CHECK.

◆ solve() [2/2]

template<int D>

void Pscf::Rpc::Propagator< D >::solve ( QField const & head )

Solve the MDE for a specified initial condition.

This function solves the modified diffusion equation (MDE) for this block with a specified initial condition, which is given by the function parameter "head". The MDE is solved by repeatedly calling the step() function of the associated Block<D>.

Parameters

head	initial condition of QField at head of block

Definition at line 133 of file rpc/solvers/Propagator.tpp.

References Util::Array< Data >::capacity(), and UTIL_CHECK.

◆ computeQ()

template<int D>

double Pscf::Rpc::Propagator< D >::computeQ ( )

Compute and return partition function for the polymer.

This function computes the partition function Q for the molecule as a spatial average of pointwise product of the initial/head Qfield for this propagator and the final/tail Qfield of its partner.

Returns: value of Q (spatial average of q*q^{+} at head)

Definition at line 155 of file rpc/solvers/Propagator.tpp.

References Util::Array< Data >::capacity(), UTIL_CHECK, and UTIL_THROW.

◆ q()

template<int D>

Propagator< D >::QField const & Pscf::Rpc::Propagator< D >::q ( int i ) const

inline

Return q-field at specified step.

Parameters

i	step index, 0 <= i < ns

Definition at line 264 of file rpc/solvers/Propagator.h.

Referenced by Pscf::Rpc::System< D >::writeQ(), and Pscf::Rpc::System< D >::writeQSlice().

◆ head()

template<int D>

Propagator< D >::QField const & Pscf::Rpc::Propagator< D >::head ( ) const

inline

Return q-field at beginning of the block (initial condition).

Definition at line 248 of file rpc/solvers/Propagator.h.

◆ tail()

template<int D>

Propagator< D >::QField const & Pscf::Rpc::Propagator< D >::tail ( ) const

inline

Return q-field at the end of the block.

Definition at line 256 of file rpc/solvers/Propagator.h.

Referenced by Pscf::Rpc::System< D >::writeQTail().

◆ block()

template<int D>

Block< D > & Pscf::Rpc::Propagator< D >::block ( )

inline

Get the associated Block object by reference.

Definition at line 272 of file rpc/solvers/Propagator.h.

◆ ns()

template<int D>

int Pscf::Rpc::Propagator< D >::ns ( ) const

inline

Number of values of s (or slices), including head and tail.

The value of ns is the number of values of s at which q(r,s) is calculated, including the end values at the terminating vertices (the head and tail). This is one more than the number of contour variable steps.

Definition at line 282 of file rpc/solvers/Propagator.h.

Referenced by Pscf::Rpc::System< D >::writeQ().

◆ isAllocated()

template<int D>

bool Pscf::Rpc::Propagator< D >::isAllocated ( ) const

inline

Has memory been allocated for this propagator?

Definition at line 286 of file rpc/solvers/Propagator.h.

◆ computeHead()

template<int D>

void Pscf::Rpc::Propagator< D >::computeHead ( )

protected

Compute initial QField at head from tail QFields of sources.

Definition at line 90 of file rpc/solvers/Propagator.tpp.

References UTIL_THROW.

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

Public Types

Public Member Functions

Protected Member Functions

Detailed Description

Member Typedef Documentation

◆ Field

◆ WField

◆ CField

◆ QField

Constructor & Destructor Documentation

◆ Propagator()

◆ ~Propagator()

Member Function Documentation

◆ setBlock()

◆ allocate()

◆ reallocate()

◆ solve() [1/2]

◆ solve() [2/2]

◆ computeQ()

◆ q()

◆ head()

◆ tail()

◆ block()

◆ ns()

◆ isAllocated()

◆ computeHead()