Parallel Colt 0.7.2

cern.colt.matrix.tfloat.algo.solver.preconditioner
Class FloatSSOR

java.lang.Object
  extended by cern.colt.matrix.tfloat.algo.solver.preconditioner.FloatSSOR
All Implemented Interfaces:
FloatPreconditioner

public class FloatSSOR
extends Object
implements FloatPreconditioner

SSOR preconditioner. Uses symmetrical sucessive overrelaxation as a preconditioner. Meant for symmetrical, positive definite matrices. For best performance, omega must be carefully chosen (between 0 and 2).


Constructor Summary
FloatSSOR(RCFloatMatrix2D F)
          Constructor for SSOR.
FloatSSOR(RCFloatMatrix2D F, boolean reverse, float omegaF, float omegaR)
          Constructor for SSOR
 
Method Summary
 FloatMatrix1D apply(FloatMatrix1D b, FloatMatrix1D x)
          Solves the approximate problem with the given right hand side.
 void setMatrix(FloatMatrix2D A)
          Sets the operator matrix for the preconditioner.
 void setOmega(float omegaF, float omegaR)
          Sets the overrelaxation parameters
 FloatMatrix1D transApply(FloatMatrix1D b, FloatMatrix1D 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

FloatSSOR

public FloatSSOR(RCFloatMatrix2D F,
                 boolean reverse,
                 float omegaF,
                 float omegaR)
Constructor for SSOR

Parameters:
F - Matrix to use internally. It will not be modified, thus the system matrix may be passed
reverse - True to perform a reverse sweep as well as the forward sweep. If false, this preconditioner becomes the SOR method instead
omegaF - Overrelaxation parameter for the forward sweep. Between 0 and 2.
omegaR - Overrelaxation parameter for the backwards sweep. Between 0 and 2.

FloatSSOR

public FloatSSOR(RCFloatMatrix2D F)
Constructor for SSOR. Uses omega=1 with a backwards sweep

Parameters:
F - Matrix to use internally. It will not be modified, thus the system matrix may be passed
Method Detail

setOmega

public void setOmega(float omegaF,
                     float omegaR)
Sets the overrelaxation parameters

Parameters:
omegaF - Overrelaxation parameter for the forward sweep. Between 0 and 2.
omegaR - Overrelaxation parameter for the backwards sweep. Between 0 and 2.

setMatrix

public void setMatrix(FloatMatrix2D A)
Description copied from interface: FloatPreconditioner
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 FloatPreconditioner
Parameters:
A - Matrix to setup the preconditioner for. Not modified

apply

public FloatMatrix1D apply(FloatMatrix1D b,
                           FloatMatrix1D x)
Description copied from interface: FloatPreconditioner
Solves the approximate problem with the given right hand side. Result is stored in given solution vector

Specified by:
apply in interface FloatPreconditioner
Parameters:
b - Right hand side of problem
x - Result is stored here
Returns:
x

transApply

public FloatMatrix1D transApply(FloatMatrix1D b,
                                FloatMatrix1D x)
Description copied from interface: FloatPreconditioner
Solves the approximate transpose problem with the given right hand side. Result is stored in given solution vector

Specified by:
transApply in interface FloatPreconditioner
Parameters:
b - Right hand side of problem
x - Result is stored here
Returns:
x

Parallel Colt 0.7.2

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