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

#include <Propagator.h>

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

Public Types
using	Base = PropagatorTmpl< Propagator<D> >
	Base class (partial template specialization).
using	FieldT = RField<D>
	Field type (function of position, defined on a r-space grid).

Public Member Functions
	Propagator ()
	Constructor.
	~Propagator ()
	Destructor.
void	setBlock (Block< D > &block)
	Associate this propagator with a 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 (FieldT const &head)
	Solve the MDE for a specified initial condition.
double	computeQ () const
	Compute and return partition function for the polymer.
const FieldT &	q (int i) const
	Return q-field at specified step.
const FieldT &	head () const
	Return q-field at beginning of the block (initial condition).
const FieldT &	tail () const
	Return q-field at the end of the block.
Block< D > const &	block () const
	Get the associated Block object by const reference.
int	ns () const
	Get the number of values of s (or slices), including head and tail.
bool	isAllocated () const
	Has memory been allocated for this propagator?
int	nSource () const
	Number of source / prerequisite propagators.
const Propagator< D > &	source (int id) const
	Get a source propagator.
const Propagator< D > &	partner () const
	Get partner propagator.
void	setIsSolved (bool isSolved)
	Set the isSolved flag to true or false.
bool	isSolved () const
	Has the modified diffusion equation been solved?
bool	hasPartner () const
	Does this have a partner propagator?
bool	isHeadEnd () const
	Is the head vertex a chain end?
bool	isTailEnd () const
	Is the tail vertex a chain end?
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.
void	setEndFlags (bool isHeadEnd, bool isTailEnd)
	Set flags indicating whether vertices are chain ends.
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	isHeadEnd () const
	Is the head vertex a chain end?
bool	isTailEnd () const
	Is the tail vertex a chain end?
bool	isSolved () const
	Has the modified diffusion equation been solved?
bool	isReady () const
	Are all source propagators solved?

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 associations with a Block<D> object that owns this propagator and its partner, and with a partner Propagator<D> that solves the MDE within the same block in the opposite direction. It also has an association with a Mesh<D> that describes a spatial grid, and associations with zero or more source Propagator<D> objects that are used to compute an initial condition for this propagator at the head vertex.

The associated Block<D> stores information required to numerically solve the modified diffusion equation (MDE), including quantities that depend upon the w-field associated with this block, the unit cell parameters and (in the thread model) the contour step size. These quantities are set and stored by the block because their values are the same for the two propagators owned by each block, but may be different for different blocks. The algorithm used by a Propagator to solve the MDE repeatedly calls step functions provided by the parent Block.

Definition at line 51 of file rpc/solvers/Propagator.h.

Member Typedef Documentation

◆ Base

template<int D>

using Pscf::Rpc::Propagator< D >::Base = PropagatorTmpl< Propagator<D> >

Base class (partial template specialization).

Definition at line 61 of file rpc/solvers/Propagator.h.

◆ FieldT

template<int D>

using Pscf::Rpc::Propagator< D >::FieldT = RField<D>

Field type (function of position, defined on a r-space grid).

Definition at line 66 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 block.

Parameters

block associated Block object.

Definition at line 300 of file rpc/solvers/Propagator.h.

References block(), and UTIL_ASSERT.

◆ 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 at vertices)
mesh	spatial discretization mesh

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

References Pscf::Mesh< D >::dimensions(), ns(), 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, which can occur during some parameter sweeps. See docs for allocate and ns.

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 ns(), setIsSolved(), and 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 q-field at the head of this block, and then solves the modified diffusion equation (MDE) to propagate the solution from the head to the tail. Algorithms for the thread or bead model may be used, depending on the value of PolymerModel::model().

Definition at line 136 of file rpc/solvers/Propagator.tpp.

References Pscf::assign(), block(), isAllocated(), Pscf::PolymerModel::isBead(), isHeadEnd(), isTailEnd(), Pscf::PolymerModel::isThread(), setIsSolved(), UTIL_CHECK, and UTIL_THROW.

◆ solve() [2/2]

template<int D>

void Pscf::Rpc::Propagator< D >::solve ( FieldT 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".

Parameters

head	initial condition of q-field at head of block

Definition at line 187 of file rpc/solvers/Propagator.tpp.

References Pscf::assign(), block(), head(), Pscf::PolymerModel::isBead(), isHeadEnd(), isTailEnd(), Pscf::PolymerModel::isThread(), setIsSolved(), UTIL_CHECK, and UTIL_THROW.

◆ computeQ()

template<int D>

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

Compute and return partition function for the polymer.

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

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

Definition at line 243 of file rpc/solvers/Propagator.tpp.

References hasPartner(), head(), Pscf::PolymerModel::isBead(), isHeadEnd(), isSolved(), isTailEnd(), partner(), UTIL_CHECK, and UTIL_THROW.

◆ q()

template<int D>

Propagator< D >::FieldT 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 268 of file rpc/solvers/Propagator.h.

References isSolved(), and UTIL_CHECK.

Referenced by Pscf::Rpc::Block< D >::computeConcentrationBead(), Pscf::Rpc::Block< D >::computeConcentrationThread(), Pscf::Rpc::Block< D >::computeStressBead(), and Pscf::Rpc::Block< D >::computeStressThread().

◆ head()

template<int D>

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

inline

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

Definition at line 246 of file rpc/solvers/Propagator.h.

References isSolved(), and UTIL_CHECK.

Referenced by computeQ(), and solve().

◆ tail()

template<int D>

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

inline

Return q-field at the end of the block.

This function throws an Exception if invoked while the bead model is in use (i.e., if PolymerModel::isThread() == false) and the tail for this propagator is a chain end (i.e., if isTailEnd() == true). In this case, the tail slice is not needed, and so is not computed.

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

References isSolved(), isTailEnd(), Pscf::PolymerModel::isThread(), and UTIL_CHECK.

◆ block()

template<int D>

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

inline

Get the associated Block object by const reference.

Definition at line 279 of file rpc/solvers/Propagator.h.

References UTIL_ASSERT.

Referenced by setBlock(), solve(), and solve().

◆ ns()

template<int D>

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

inline

Get the 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). In the bead model, this is two more than the number of beads in the block. In the thread model, this is one more than the number length/ds of contour length steps.

Definition at line 289 of file rpc/solvers/Propagator.h.

Referenced by allocate(), and reallocate().

◆ isAllocated()

template<int D>

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

inline

Has memory been allocated for this propagator?

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

Referenced by Pscf::Rpc::Block< D >::computeStressThread(), and solve().

◆ nSource()

template<int D>

int Pscf::PropagatorTmpl< Propagator< D > >::nSource ( ) const

Number of source / prerequisite propagators.

◆ source()

template<int D>

const Propagator< D > & Pscf::PropagatorTmpl< Propagator< D > >::source ( int id ) const

Get a source propagator.

Parameters

id	index of source propagator, < nSource

◆ partner()

template<int D>

const Propagator< D > & Pscf::PropagatorTmpl< Propagator< D > >::partner ( ) const

Get partner propagator.

Referenced by computeQ().

◆ setIsSolved()

template<int D>

void Pscf::PropagatorTmpl< Propagator< D > >::setIsSolved ( bool isSolved )

Set the isSolved flag to true or false.

Referenced by reallocate(), solve(), and solve().

◆ isSolved()

template<int D>

bool Pscf::PropagatorTmpl< Propagator< D > >::isSolved ( ) const

Has the modified diffusion equation been solved?

Referenced by computeQ(), Pscf::Rpc::Block< D >::computeStressBead(), head(), q(), and tail().

◆ hasPartner()

template<int D>

bool Pscf::PropagatorTmpl< Propagator< D > >::hasPartner ( ) const

Does this have a partner propagator?

Referenced by computeQ().

◆ isHeadEnd()

template<int D>

bool Pscf::PropagatorTmpl< Propagator< D > >::isHeadEnd ( ) const

Is the head vertex a chain end?

Precondition: PolymerModel::isBead()

Referenced by computeQ(), Pscf::Rpc::Block< D >::computeStressBead(), solve(), and solve().

◆ isTailEnd()

template<int D>

bool Pscf::PropagatorTmpl< Propagator< D > >::isTailEnd ( ) const

Is the tail vertex a chain end?

Precondition: PolymerModel::isBead()

Referenced by computeQ(), Pscf::Rpc::Block< D >::computeStressBead(), solve(), solve(), and tail().

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

Public Types

Public Member Functions

Detailed Description

Member Typedef Documentation

◆ Base

◆ FieldT

Constructor & Destructor Documentation

◆ Propagator()

◆ ~Propagator()

Member Function Documentation

◆ setBlock()

◆ allocate()

◆ reallocate()

◆ solve() [1/2]

◆ solve() [2/2]

◆ computeQ()

◆ q()

◆ head()

◆ tail()

◆ block()

◆ ns()

◆ isAllocated()

◆ nSource()

◆ source()

◆ partner()

◆ setIsSolved()

◆ isSolved()

◆ hasPartner()

◆ isHeadEnd()

◆ isTailEnd()