Reference documentation for deal.II version GIT relicensing662g00096bcf61 20240518 15:40:02+00:00

#include <deal.II/lac/petsc_solver.h>
Classes  
struct  AdditionalData 
Public Member Functions  
SparseDirectMUMPS (SolverControl &cn, const AdditionalData &data=AdditionalData())  
SparseDirectMUMPS (SolverControl &cn, const MPI_Comm mpi_communicator, const AdditionalData &data=AdditionalData())  
void  solve (const MatrixBase &A, VectorBase &x, const VectorBase &b) 
void  set_symmetric_mode (const bool matrix_is_symmetric) 
void  solve (const MatrixBase &A, VectorBase &x, const VectorBase &b, const PreconditionBase &preconditioner) 
virtual void  reset () 
void  set_prefix (const std::string &prefix) 
SolverControl &  control () const 
void  initialize (const PreconditionBase &preconditioner) 
KSP  petsc_ksp () 
operator KSP () const  
Protected Member Functions  
virtual void  set_solver_type (KSP &ksp) const override 
void  initialize_ksp_with_comm (const MPI_Comm comm) 
void  perhaps_set_convergence_test () const 
Protected Attributes  
const AdditionalData  additional_data 
bool  symmetric_mode 
KSP  ksp 
SmartPointer< SolverControl, SolverBase >  solver_control 
std::string  prefix_name 
Static Private Member Functions  
static PetscErrorCode  convergence_test (KSP ksp, const PetscInt iteration, const PetscReal residual_norm, KSPConvergedReason *reason, void *solver_control) 
An implementation of the solver interface using the sparse direct MUMPS solver through PETSc. This class has the usual interface of all other solver classes but it is of course different in that it doesn't implement an iterative solver. As a consequence, things like the SolverControl object have no particular meaning here.
MUMPS allows to make use of symmetry in this matrix. In this class this is made possible by the set_symmetric_mode() function. If your matrix is symmetric, you can use this class as follows:
Definition at line 903 of file petsc_solver.h.
PETScWrappers::SparseDirectMUMPS::SparseDirectMUMPS  (  SolverControl &  cn, 
const AdditionalData &  data = AdditionalData() 

) 
Constructor.
Definition at line 641 of file petsc_solver.cc.
PETScWrappers::SparseDirectMUMPS::SparseDirectMUMPS  (  SolverControl &  cn, 
const MPI_Comm  mpi_communicator,  
const AdditionalData &  data = AdditionalData() 

) 
Constructor. This constructor is deprecated and ignores the MPI communicator argument. Use the other constructor instead.
Definition at line 650 of file petsc_solver.cc.
void PETScWrappers::SparseDirectMUMPS::solve  (  const MatrixBase &  A, 
VectorBase &  x,  
const VectorBase &  b  
) 
The method to solve the linear system.
Definition at line 684 of file petsc_solver.cc.
void PETScWrappers::SparseDirectMUMPS::set_symmetric_mode  (  const bool  matrix_is_symmetric  ) 
If called with true
as argument, tell the direct solver to assume that the system matrix is symmetric. It does so by computing the LDL^T decomposition (in effect, a Cholesky decomposition) instead of more expensive LU decomposition. The argument indicates whether the matrix can be assumed to be symmetric or not.
Note that most finite element matrices are "structurally symmetric", i.e., the sparsity pattern is symmetric, even though the matrix is not. An example of a matrix that is structurally symmetric but not symmetric is the matrix you obtain by discretizing the advection equation \(\nabla \cdot (\vec\beta u) = f\) (see, for example step12). Because the operator here is not symmetric, the matrix is not symmetric either; however, if matrix entry \(A_{ij}\) is nonzero, then matrix entry \(A_{ji}\) is generally not zero either (and in any case, DoFTools::make_sparsity_pattern() will create a symmetric sparsity pattern). That said, the current function is not meant to indicate whether the sparsity pattern is symmetric, but whether the matrix itself is symmetric, and this typically requires that the differential operator you are considering is symmetric.
Definition at line 814 of file petsc_solver.cc.

overrideprotectedvirtual 
Function that takes a Krylov Subspace Solver context object, and sets the type of solver that is requested by the derived class.
Reimplemented from PETScWrappers::SolverBase.
Definition at line 659 of file petsc_solver.cc.

inherited 
Solve the linear system Ax=b
. Depending on the information provided by derived classes and the object passed as a preconditioner, one of the linear solvers and preconditioners of PETSc is chosen. Repeated calls to solve() do not reconstruct the preconditioner for performance reasons. See class Documentation.
Definition at line 83 of file petsc_solver.cc.

virtualinherited 
Resets the contained preconditioner and solver object. See class description for more details.
Definition at line 148 of file petsc_solver.cc.

inherited 
Sets a prefix name for the solver object. Useful when customizing the PETSc KSP object with commandline options.
Definition at line 141 of file petsc_solver.cc.

inherited 
Access to object that controls convergence.
Definition at line 155 of file petsc_solver.cc.

inherited 
initialize the solver with the preconditioner. This function is intended for use with SLEPc spectral transformation class.
Definition at line 231 of file petsc_solver.cc.

inherited 
Return the PETSc KSP object.
Definition at line 68 of file petsc_solver.cc.

inherited 
Conversion operator to gain access to the underlying PETSc type. If you do this, you cut this class off some information it may need, so this conversion operator should only be used if you know what you do.
Definition at line 75 of file petsc_solver.cc.

protectedinherited 
Utility to create the KSP object and attach convergence test.
Definition at line 206 of file petsc_solver.cc.

protectedinherited 
Utility to use deal.II convergence testing.
This call changes the convergence criterion when the instance of the class has a SolverControl object associated.
Definition at line 222 of file petsc_solver.cc.

staticprivateinherited 
A function that is used in PETSc as a callback to check on convergence. It takes the information provided from PETSc and checks it against deal.II's own SolverControl objects to see if convergence has been reached.
Definition at line 166 of file petsc_solver.cc.

protected 
Store a copy of flags for this particular solver.
Definition at line 965 of file petsc_solver.h.

protected 
Flag specifies whether matrix being factorized is symmetric or not. It influences the type of the used preconditioner (PCLU or PCCHOLESKY)
Definition at line 974 of file petsc_solver.h.

protectedinherited 
The PETSc KSP object.
Definition at line 167 of file petsc_solver.h.

protectedinherited 
Reference to the object that controls convergence of the iterative solver. In fact, for these PETSc wrappers, PETSc does so itself, but we copy the data from this object before starting the solution process, and copy the data back into it afterwards.
Definition at line 175 of file petsc_solver.h.

protectedinherited 
Solver prefix name to qualify options specific to the PETSc KSP object in the current context. Note: A hyphen () must NOT be given at the beginning of the prefix name. The first character of all runtime options is AUTOMATICALLY the hyphen.
Definition at line 205 of file petsc_solver.h.