no.uib.cipr.matrix.sparse

Class QMR

java.lang.Object

no.uib.cipr.matrix.sparse.AbstractIterativeSolver

no.uib.cipr.matrix.sparse.QMR

All Implemented Interfaces:

IterativeSolver

public class QMR
extends AbstractIterativeSolver

Quasi-Minimal Residual method. QMR solves the unsymmetric linear system Ax = b using the Quasi-Minimal Residual method. QMR uses two preconditioners, and by default these are the same preconditioner.

Author:

Templates

Field Summary

Fields inherited from class no.uib.cipr.matrix.sparse.AbstractIterativeSolver

iter, M

Constructor Summary

Constructors

Constructor and Description
QMR(Vector template) Constructor for QMR.
QMR(Vector template, Preconditioner M1, Preconditioner M2) Constructor for QMR.

Method Summary

Modifier and Type	Method and Description
void	setPreconditioner(Preconditioner M) Sets preconditioner
Vector	solve(Matrix A, Vector b, Vector x) Solves the given problem, writing result into the vector.

Methods inherited from class no.uib.cipr.matrix.sparse.AbstractIterativeSolver

checkSizes, getIterationMonitor, getPreconditioner, setIterationMonitor

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

QMR

public QMR(Vector template)

Constructor for QMR. Uses the given vector as template for creating scratch vectors. Typically, the solution or the right hand side vector can be passed, and the template is not modified

Parameters:

template - Vector to use as template for the work vectors needed in the solution process

QMR

public QMR(Vector template,
           Preconditioner M1,
           Preconditioner M2)

Constructor for QMR. Uses the given vector as template for creating scratch vectors. Typically, the solution or the right hand side vector can be passed, and the template is not modified. Allows setting different right and left preconditioners

Parameters:

template - Vector to use as template for the work vectors needed in the solution process

M1 - Left preconditioner

M2 - Right preconditioner

Method Detail

solve

public Vector solve(Matrix A,
                    Vector b,
                    Vector x)
             throws IterativeSolverNotConvergedException

Description copied from interface: IterativeSolver

Solves the given problem, writing result into the vector.

Parameters:

A - Matrix of the problem

b - Right hand side

x - Solution is stored here. Also used as initial guess

Returns:

The solution vector x

Throws:

IterativeSolverNotConvergedException

setPreconditioner

public void setPreconditioner(Preconditioner M)

Description copied from interface: IterativeSolver

Sets preconditioner

Specified by:

setPreconditioner in interface IterativeSolver

Overrides:

setPreconditioner in class AbstractIterativeSolver

Parameters:

M - Preconditioner to use