cern.colt.matrix.tdouble.algo.solver.preconditioner
Class DoubleDiagonal

java.lang.Object
  cern.colt.matrix.tdouble.algo.solver.preconditioner.DoubleDiagonal

All Implemented Interfaces:

DoublePreconditioner

public class DoubleDiagonal
extends Object
implements DoublePreconditioner

Diagonal preconditioner. Uses the inverse of the diagonal as preconditioner

Constructor Summary

DoubleDiagonal(int n)
Constructor for DiagonalPreconditioner

Method Summary

DoubleMatrix1D	apply(DoubleMatrix1D b, DoubleMatrix1D x) Solves the approximate problem with the given right hand side.
void	setMatrix(DoubleMatrix2D A) Sets the operator matrix for the preconditioner.
DoubleMatrix1D	transApply(DoubleMatrix1D b, DoubleMatrix1D x) Solves the approximate transpose problem with the given right hand side.

Methods inherited from class java.lang.Object

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

Constructor Detail

DoubleDiagonal

public DoubleDiagonal(int n)

Constructor for DiagonalPreconditioner

Parameters:

n - Problem size (number of rows)

Method Detail

apply

public DoubleMatrix1D apply(DoubleMatrix1D b,
                            DoubleMatrix1D x)

Description copied from interface: DoublePreconditioner

Solves the approximate problem with the given right hand side. Result is stored in given solution vector

Specified by:

apply in interface DoublePreconditioner

Parameters:

b - Right hand side of problem

x - Result is stored here

Returns:

x

transApply

public DoubleMatrix1D transApply(DoubleMatrix1D b,
                                 DoubleMatrix1D x)

Description copied from interface: DoublePreconditioner

Solves the approximate transpose problem with the given right hand side. Result is stored in given solution vector

Specified by:

transApply in interface DoublePreconditioner

Parameters:

b - Right hand side of problem

x - Result is stored here

Returns:

x

setMatrix

public void setMatrix(DoubleMatrix2D A)

Description copied from interface: DoublePreconditioner

Sets the operator matrix for the preconditioner. This method must be called before a preconditioner is used by an iterative solver

Specified by:

setMatrix in interface DoublePreconditioner

Parameters:

A - Matrix to setup the preconditioner for. Not modified