org.apache.commons.math3.linear
Class IterativeLinearSolverEvent

java.lang.Object
  extended by java.util.EventObject
      extended by org.apache.commons.math3.util.IterationEvent
          extended by org.apache.commons.math3.linear.IterativeLinearSolverEvent
All Implemented Interfaces:
Serializable
Direct Known Subclasses:
DefaultIterativeLinearSolverEvent

public abstract class IterativeLinearSolverEvent
extends IterationEvent

This is the base class for all events occuring during the iterations of a IterativeLinearSolver.

Since:
3.0
Version:
$Id: IterativeLinearSolverEvent.java 1416643 2012-12-03 19:37:14Z tn $
See Also:
Serialized Form

Field Summary
 
Fields inherited from class java.util.EventObject
source
 
Constructor Summary
IterativeLinearSolverEvent(Object source, int iterations)
          Creates a new instance of this class.
 
Method Summary
abstract  double getNormOfResidual()
          Returns the norm of the residual.
 RealVector getResidual()
           Returns the residual.
abstract  RealVector getRightHandSideVector()
          Returns the current right-hand side of the linear system to be solved.
abstract  RealVector getSolution()
          Returns the current estimate of the solution to the linear system to be solved.
 boolean providesResidual()
          Returns true if getResidual() is supported.
 
Methods inherited from class org.apache.commons.math3.util.IterationEvent
getIterations
 
Methods inherited from class java.util.EventObject
getSource, toString
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

IterativeLinearSolverEvent

public IterativeLinearSolverEvent(Object source,
                                  int iterations)
Creates a new instance of this class.

Parameters:
source - the iterative algorithm on which the event initially occurred
iterations - the number of iterations performed at the time this event is created
Method Detail

getRightHandSideVector

public abstract RealVector getRightHandSideVector()
Returns the current right-hand side of the linear system to be solved. This method should return an unmodifiable view, or a deep copy of the actual right-hand side vector, in order not to compromise subsequent iterations of the source IterativeLinearSolver.

Returns:
the right-hand side vector, b

getNormOfResidual

public abstract double getNormOfResidual()
Returns the norm of the residual. The returned value is not required to be exact. Instead, the norm of the so-called updated residual (if available) should be returned. For example, the conjugate gradient method computes a sequence of residuals, the norm of which is cheap to compute. However, due to accumulation of round-off errors, this residual might differ from the true residual after some iterations. See e.g. A. Greenbaum and Z. Strakos, Predicting the Behavior of Finite Precision Lanzos and Conjugate Gradient Computations, Technical Report 538, Department of Computer Science, New York University, 1991 (available here).

Returns:
the norm of the residual, ||r||

getResidual

public RealVector getResidual()

Returns the residual. This is an optional operation, as all iterative linear solvers do not provide cheap estimate of the updated residual vector, in which case

The default implementation throws a MathUnsupportedOperationException. If this method is overriden, then providesResidual() should be overriden as well.

Returns:
the updated residual, r

getSolution

public abstract RealVector getSolution()
Returns the current estimate of the solution to the linear system to be solved. This method should return an unmodifiable view, or a deep copy of the actual current solution, in order not to compromise subsequent iterations of the source IterativeLinearSolver.

Returns:
the solution, x

providesResidual

public boolean providesResidual()
Returns true if getResidual() is supported. The default implementation returns false.

Returns:
false if getResidual() throws a MathUnsupportedOperationException


Copyright © 2003-2012 The Apache Software Foundation. All Rights Reserved.