JacobiPreconditioner

java.lang.Object

org.ojalgo.matrix.task.iterative.JacobiPreconditioner

All Implemented Interfaces:: Preconditioner

public final class JacobiPreconditioner extends Object implements Preconditioner

Simple diagonal (Jacobi) preconditioner: M = diag(A), apply M^{-1} x = x ./ diag(A).

Compatibility

Well-suited as a lightweight, symmetry-preserving choice for methods that benefit from SPD preconditioning when A has positive diagonal entries.
Usable as a right-preconditioner in methods for general nonsymmetric systems where a transpose action equals the forward action.
Ignored by stationary fixed-point methods that do not use preconditioners.

Field Summary

Fields

Modifier and Type

Field

Description

private R064Store

myInvDiag

Fields inherited from interface Preconditioner
IDENTITY
Constructor Summary

Constructors

Constructor

Description

JacobiPreconditioner()
Method Summary

Modifier and Type

Method

Description

void

apply(Access1D<Double> src, PhysicalStore<Double> dst)

Apply M^{-1} to a vector.

void

prepare(List<Equation> equations, int dimension)

Prepare internal structures for a specific system.

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface Preconditioner
applyTranspose

Field Details
- myInvDiag
  
  private transient R064Store myInvDiag
Constructor Details
- JacobiPreconditioner
  
  public JacobiPreconditioner()
Method Details
- apply
  
  public void apply(Access1D<Double> src, PhysicalStore<Double> dst)
  
  Description copied from interface: Preconditioner
  
  Apply M^{-1} to a vector. src and dst may alias.
  
  Specified by:
  
  apply in interface Preconditioner
- prepare
  
  public void prepare(List<Equation> equations, int dimension)
  
  Description copied from interface: Preconditioner
  
  Prepare internal structures for a specific system. Implementations may analyse sparsity or extract diagonals/factors here.
  
  Specified by:
  
  prepare in interface Preconditioner
  
  Parameters:
  
  equations - The active set of rows constituting the system body.
  
  dimension - The vector dimension (number of variables / size of solution vector).