TrilinosWrappers::PreconditionChebyshev::AdditionalData Struct Reference

List of all members.

Public Member Functions

 AdditionalData (const unsigned int degree=1, const double max_eigenvalue=10., const double eigenvalue_ratio=30., const double min_eigenvalue=1., const double min_diagonal=1e-12, const bool nonzero_starting=false)

Public Attributes

unsigned int degree
double max_eigenvalue
double eigenvalue_ratio
double min_eigenvalue
double min_diagonal
bool nonzero_starting


Detailed Description

Standardized data struct to pipe additional parameters to the preconditioner.

Constructor & Destructor Documentation

TrilinosWrappers::PreconditionChebyshev::AdditionalData::AdditionalData ( const unsigned int  degree = 1,
const double  max_eigenvalue = 10.,
const double  eigenvalue_ratio = 30.,
const double  min_eigenvalue = 1.,
const double  min_diagonal = 1e-12,
const bool  nonzero_starting = false 
)

Constructor.


Member Data Documentation

This determines the degree of the Chebyshev polynomial. The degree of the polynomial gives the number of matrix-vector products to be performed for one application of the vmult() operation.

This sets the maximum eigenvalue of the matrix, which needs to be set properly for appropriate performance of the Chebyshev preconditioner.

This sets the ratio between the maximum and the minimum eigenvalue.

This sets the minimum eigenvalue, which is an optional parameter only used internally for checking whether we use an identity matrix.

This sets a threshold below which the diagonal element will not be inverted in the Chebyshev algorithm.

When this flag is set to true, it enables the method vmult(dst, src) to use non-zero data in the vector dst, appending to it the Chebyshev corrections. This can be useful in some situations (e.g. when used for high-frequency error smoothing), but not the way the solver classes expect a preconditioner to work (where one ignores the content in dst for the preconditioner application). The user should really know what she is doing when touching this flag.


The documentation for this struct was generated from the following file:

deal.II documentation generated on Sat Aug 15 16:52:53 2009 by doxygen 1.5.9