Abstract class defining the problem-specific interface for the simplified solver interface to IterativeSolver. More...

#include <IterativeSolver.h>

Inheritance diagram for molpro::linalg::itsolv::Problem< R, P >:

Detailed Description

template<typename R, typename P = std::map<size_t, typename R::value_type>>
class molpro::linalg::itsolv::Problem< R, P >

Abstract class defining the problem-specific interface for the simplified solver interface to IterativeSolver.

Template Parameters

R	the type of container for solutions and residuals

Examples: ExampleProblem.h, and ExampleProblemDistrArray.h.

Public Types
using	container_t = R

using	value_t = typename R::value_type

Public Member Functions
	Problem ()=default

virtual	~Problem ()=default

virtual value_t	residual (const R &parameters, R &residual) const
	Calculate the residual vector. Used by non-linear solvers (NonLinearEquations, Optimize) only. More...

virtual void	action (const CVecRef< R > &parameters, const VecRef< R > &action) const
	Calculate the action of the kernel matrix on a set of parameters. Used by linear solvers, but not by the non-linear solvers (NonLinearEquations, Optimize). More...

virtual bool	diagonals (container_t &d) const
	Optionally provide the diagonal elements of the underlying kernel. If implemented and returning true, the provided diagonals will be used by IterativeSolver for preconditioning (and therefore the precondition() function does not need to be implemented), and, in the case of linear problems, for selection of the P space. Otherwise, preconditioning will be done with precondition(), and any P space has to be provided manually. More...

virtual void	precondition (const VecRef< R > &residual, const std::vector< value_t > &shift) const
	Apply preconditioning to a residual vector in order to predict a step towards the solution. More...

virtual void	precondition (const VecRef< R > &residual, const std::vector< value_t > &shift, const R &diagonals) const
	Apply preconditioning to a residual vector in order to predict a step towards the solution. More...

virtual bool	RHS (R &RHS, unsigned int instance) const
	Return the inhomogeneous part of a linear equation system. More...

virtual std::vector< double >	pp_action_matrix (const std::vector< P > &pparams) const
	Calculate the kernel matrix in the P space. More...

virtual void	p_action (const std::vector< std::vector< value_t > > &p_coefficients, const CVecRef< P > &pparams, const VecRef< container_t > &actions) const
	Calculate the action of the kernel matrix on a set of vectors in the P space. More...

virtual bool	test_parameters (unsigned int instance, R &parameters) const
	Provide values of R vectors for testing the problem class. For use in a non-linear solver, the first vector (instance=0) should be a reference point, and the remainder (instance>0) should be close to it, such that meaningful numerical differentation can be done to test the residual function. More...

Member Typedef Documentation

◆ container_t

template<typename R , typename P = std::map<size_t, typename R::value_type>>

using molpro::linalg::itsolv::Problem< R, P >::container_t = R

◆ value_t

template<typename R , typename P = std::map<size_t, typename R::value_type>>

using molpro::linalg::itsolv::Problem< R, P >::value_t = typename R::value_type

Constructor & Destructor Documentation

◆ Problem()

template<typename R , typename P = std::map<size_t, typename R::value_type>>

molpro::linalg::itsolv::Problem< R, P >::Problem ( )

default

◆ ~Problem()

template<typename R , typename P = std::map<size_t, typename R::value_type>>

virtual molpro::linalg::itsolv::Problem< R, P >::~Problem ( )

virtualdefault

Member Function Documentation

◆ action()

template<typename R , typename P = std::map<size_t, typename R::value_type>>

virtual void molpro::linalg::itsolv::Problem< R, P >::action	(	const CVecRef< R > &	parameters,
		const VecRef< R > &	action
	)		const

inlinevirtual

Calculate the action of the kernel matrix on a set of parameters. Used by linear solvers, but not by the non-linear solvers (NonLinearEquations, Optimize).

Parameters

parameters	The trial solutions for which the action is to be calculated
action	The action vectors

Examples: ExampleProblem.h, and ExampleProblemDistrArray.h.

◆ diagonals()

template<typename R , typename P = std::map<size_t, typename R::value_type>>

virtual bool molpro::linalg::itsolv::Problem< R, P >::diagonals ( container_t & d ) const

inlinevirtual

Optionally provide the diagonal elements of the underlying kernel. If implemented and returning true, the provided diagonals will be used by IterativeSolver for preconditioning (and therefore the precondition() function does not need to be implemented), and, in the case of linear problems, for selection of the P space. Otherwise, preconditioning will be done with precondition(), and any P space has to be provided manually.

Parameters

d	On exit, contains the diagonal elements

Returns: Whether diagonals have been provided.

Examples: ExampleProblem.h, and ExampleProblemDistrArray.h.

◆ p_action()

template<typename R , typename P = std::map<size_t, typename R::value_type>>

virtual void molpro::linalg::itsolv::Problem< R, P >::p_action	(	const std::vector< std::vector< value_t > > &	p_coefficients,
		const CVecRef< P > &	pparams,
		const VecRef< container_t > &	actions
	)		const

inlinevirtual

Calculate the action of the kernel matrix on a set of vectors in the P space.

Parameters

p_coefficients	The projection of the vectors onto to the P space
pparams	Specification of the P space
actions	On exit, the computed action has been added to the original contents

Examples: ExampleProblemDistrArray.h.

◆ pp_action_matrix()

template<typename R , typename P = std::map<size_t, typename R::value_type>>

virtual std::vector< double > molpro::linalg::itsolv::Problem< R, P >::pp_action_matrix ( const std::vector< P > & pparams ) const

inlinevirtual

Calculate the kernel matrix in the P space.

Parameters

pparams Specification of the P space

Returns

Examples: ExampleProblemDistrArray.h.

◆ precondition() [1/2]

template<typename R , typename P = std::map<size_t, typename R::value_type>>

virtual void molpro::linalg::itsolv::Problem< R, P >::precondition	(	const VecRef< R > &	residual,
		const std::vector< value_t > &	shift
	)		const

inlinevirtual

Apply preconditioning to a residual vector in order to predict a step towards the solution.

Parameters

residual	On entry, assumed to be the residual. On exit, the negative of the predicted step.
shift	When called from LinearEigensystem, contains the corresponding current eigenvalue estimates for each of the parameter vectors in the set. All other solvers pass a vector of zeroes.

◆ precondition() [2/2]

template<typename R , typename P = std::map<size_t, typename R::value_type>>

virtual void molpro::linalg::itsolv::Problem< R, P >::precondition	(	const VecRef< R > &	residual,
		const std::vector< value_t > &	shift,
		const R &	diagonals
	)		const

inlinevirtual

Apply preconditioning to a residual vector in order to predict a step towards the solution.

Parameters

residual	On entry, assumed to be the residual. On exit, the negative of the predicted step.
shift	When called from LinearEigensystem, contains the corresponding current eigenvalue estimates for each of the parameter vectors in the set. All other solvers pass a vector of zeroes.
diagonals	The diagonal elements of the underlying kernel

◆ residual()

template<typename R , typename P = std::map<size_t, typename R::value_type>>

virtual value_t molpro::linalg::itsolv::Problem< R, P >::residual	(	const R &	parameters,
		R &	residual
	)		const

inlinevirtual

Calculate the residual vector. Used by non-linear solvers (NonLinearEquations, Optimize) only.

Parameters

parameters	The trial solution for which the residual is to be calculated
residual	The residual vector

Returns: In the case where the residual is an exact differential, the corresponding function value. Used by Optimize but not NonLinearEquations.

Reimplemented in Morse_problem.

Examples: ExampleProblem.h, and ExampleProblemDistrArray.h.

◆ RHS()

template<typename R , typename P = std::map<size_t, typename R::value_type>>

virtual bool molpro::linalg::itsolv::Problem< R, P >::RHS	(	R &	RHS,
		unsigned int	instance
	)		const

inlinevirtual

Return the inhomogeneous part of a linear equation system.

Parameters

RHS	On return, will contain the requested right-hand-side of equations if available.
instance	Which RHS is required. If there are N sets of equations to solve, then 0,1,...N-1 number the instances. The solver will call this function repeatedly with instance=0,1,2,... until it receives a negative response.

Returns: whether the requested RHS is available and has been provided

Examples: ExampleProblem.h.

◆ test_parameters()

template<typename R , typename P = std::map<size_t, typename R::value_type>>

virtual bool molpro::linalg::itsolv::Problem< R, P >::test_parameters	(	unsigned int	instance,
		R &	parameters
	)		const

inlinevirtual

Provide values of R vectors for testing the problem class. For use in a non-linear solver, the first vector (instance=0) should be a reference point, and the remainder (instance>0) should be close to it, such that meaningful numerical differentation can be done to test the residual function.

Parameters

instance
parameters

Returns: true if a vector has been provided

Detailed Description

Public Types

Public Member Functions

Member Typedef Documentation

◆ container_t

◆ value_t

Constructor & Destructor Documentation

◆ Problem()

◆ ~Problem()

Member Function Documentation

◆ action()

◆ diagonals()

◆ p_action()

◆ pp_action_matrix()

◆ precondition() [1/2]

◆ precondition() [2/2]

◆ residual()

◆ RHS()

◆ test_parameters()