quda::MinResExt Class Reference

This computes the optimum guess for the system Ax=b in the L2 residual norm. For use in the HMD force calculations using a minimal residual chronological method. This computes the guess solution as a linear combination of a given number of previous solutions. Following Brower et al, only the orthogonalised vector basis is stored to conserve memory. More...

#include <invert_quda.h>

Public Member Functions
	MinResExt (const DiracMatrix &mat, bool orthogonal, bool apply_mat, bool hermitian, TimeProfile &profile)
virtual	~MinResExt ()
void	operator() (ColorSpinorField &x, ColorSpinorField &b, std::vector< std::pair< ColorSpinorField *, ColorSpinorField * > > basis)
void	operator() (ColorSpinorField &x, ColorSpinorField &b, std::vector< ColorSpinorField * > p, std::vector< ColorSpinorField * > q)

Protected Member Functions
void	solve (Complex *psi_, std::vector< ColorSpinorField * > &p, std::vector< ColorSpinorField * > &q, ColorSpinorField &b, bool hermitian)
	Solve the equation A p_k psi_k = q_k psi_k = b by minimizing the residual and using Eigen's SVD algorithm for numerical stability. More...

Protected Attributes
const DiracMatrix &	mat
bool	orthogonal
bool	apply_mat
	Whether to construct an orthogonal basis or not. More...
bool	hermitian
	Whether to compute q = Ap or assume it is provided. More...
TimeProfile &	profile
	whether A is hermitian ot not More...

Detailed Description

This computes the optimum guess for the system Ax=b in the L2 residual norm. For use in the HMD force calculations using a minimal residual chronological method. This computes the guess solution as a linear combination of a given number of previous solutions. Following Brower et al, only the orthogonalised vector basis is stored to conserve memory.

If Eigen support is enabled then Eigen's SVD algorithm is used for solving the linear system, else Gaussian elimination with partial pivots is used.

Definition at line 1303 of file invert_quda.h.

Constructor & Destructor Documentation

MinResExt()

quda::MinResExt::MinResExt	(	const DiracMatrix &	mat,
		bool	orthogonal,
		bool	apply_mat,
		bool	hermitian,
		TimeProfile &	profile
	)

Parameters

mat	The operator for the linear system we wish to solve
orthogonal	Whether to construct an orthogonal basis prior to constructing the linear system
apply_mat	Whether to apply the operator in place or assume q already contains this @profile Timing profile to use

Definition at line 7 of file inv_mre.cpp.

~MinResExt()

quda::MinResExt::~MinResExt ( )

virtual

Definition at line 16 of file inv_mre.cpp.

Member Function Documentation

operator()() [1/2]

void quda::MinResExt::operator()	(	ColorSpinorField &	x,
		ColorSpinorField &	b,
		std::vector< ColorSpinorField * >	p,
		std::vector< ColorSpinorField * >	q
	)

Parameters

x	The optimum for the solution vector.
b	The source vector in the equation to be solved. This is not preserved.
p	The basis vectors in which we are building the guess
q	The basis vectors multiplied by A

Definition at line 85 of file inv_mre.cpp.

operator()() [2/2]

void quda::MinResExt::operator()	(	ColorSpinorField &	x,
		ColorSpinorField &	b,
		std::vector< std::pair< ColorSpinorField *, ColorSpinorField * > >	basis
	)

Parameters

x	The optimum for the solution vector.
b	The source vector in the equation to be solved. This is not preserved and is overwritten by the new residual.
basis	Vector of pairs storing the basis (p,Ap)

Definition at line 169 of file inv_mre.cpp.

solve()

void quda::MinResExt::solve ( Complex *  psi_, std::vector< ColorSpinorField * > &  p, std::vector< ColorSpinorField * > &  q, ColorSpinorField &  b, bool  hermitian  )

protected

Solve the equation A p_k psi_k = q_k psi_k = b by minimizing the residual and using Eigen's SVD algorithm for numerical stability.

Parameters

[out]	psi	Array of coefficients
[in]	p	Search direction vectors
[in]	q	Search direction vectors with the operator applied
[in]	hermitian	Whether the linear system is Hermitian or not

Definition at line 22 of file inv_mre.cpp.

Member Data Documentation

apply_mat

bool quda::MinResExt::apply_mat

protected

Whether to construct an orthogonal basis or not.

Definition at line 1308 of file invert_quda.h.

hermitian

bool quda::MinResExt::hermitian

protected

Whether to compute q = Ap or assume it is provided.

Definition at line 1309 of file invert_quda.h.

mat

const DiracMatrix& quda::MinResExt::mat

protected

Definition at line 1306 of file invert_quda.h.

orthogonal

bool quda::MinResExt::orthogonal

protected

Definition at line 1307 of file invert_quda.h.

profile

TimeProfile& quda::MinResExt::profile

protected

whether A is hermitian ot not

Definition at line 1310 of file invert_quda.h.

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

• quda/include/invert_quda.h
• quda/lib/inv_mre.cpp