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Reference documentation for deal.II version 8.1.0
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Classes | |
class | SolverBase |
class | SolverKrylovSchur |
class | SolverArnoldi |
class | SolverLanczos |
class | SolverPower |
class | SolverGeneralizedDavidson |
class | SolverJacobiDavidson |
class | SolverLAPACK |
class | TransformationBase |
class | TransformationShift |
class | TransformationShiftInvert |
class | TransformationSpectrumFolding |
class | TransformationCayley |
Base class for solver classes using the SLEPc solvers which are selected based on flags passed to the eigenvalue problem solver context. Derived classes set the right flags to set the right solver. Note that: the AdditionalData
structure is a dummy structure that currently exists for backward/forward compatibility only.
The SLEPc solvers are intended to be used for solving the generalized eigenspectrum problem , for
; where
is a system matrix,
is a mass matrix, and
are a set of eigenvalues and eigenvectors respectively. The emphasis is on methods and techniques appropriate for problems in which the associated matrices are sparse. Most of the methods offered by the SLEPc library are projection methods or other methods with similar properties; and wrappers are provided to interface to SLEPc solvers that handle both of these problem sets.
SLEPcWrappers can be implemented in application codes in the following way:
for the generalized eigenvalue problem , where the variable
const unsigned int size_of_spectrum
tells SLEPc the number of eigenvector/eigenvalue pairs to solve for. Additional options and solver parameters can be passed to the SLEPc solvers before calling solve()
. For example, if the matrices of the general eigenspectrum problem are not hermitian and the lower eigenvalues are wanted only, the following code can be implemented before calling solve()
:
These options can also be set at the commandline.
See also step-36
for a hands-on example.
An alternative implementation to the one above is to use the API internals directly within the application code. In this way the calling sequence requires calling several of SolverBase functions rather than just one. This freedom is intended for use of the SLEPcWrappers that require a greater handle on the eigenvalue problem solver context. See also the API of, for example:
as an example on how to do this.
For further information and explanations on handling the SLEPcWrappers, see also the PETScWrappers, on which they depend.