Amesos_BaseSolver: A pure virtual class for direct solution of real-valued double-precision operators. More...
#include <Amesos_BaseSolver.h>
Public Member Functions | |
virtual | ~Amesos_BaseSolver () |
Destructor. | |
virtual int | SymbolicFactorization ()=0 |
Performs SymbolicFactorization on the matrix A. | |
virtual int | NumericFactorization ()=0 |
Performs NumericFactorization on the matrix A. | |
virtual int | Solve ()=0 |
Solves A X = B (or A^{T} x = B). | |
virtual int | SetUseTranspose (bool UseTranspose)=0 |
If set true, X will be set to the solution of A^{T} X = B (not A X = B). | |
virtual bool | UseTranspose () const =0 |
Returns the current UseTranspose setting. | |
virtual int | SetParameters (Teuchos::ParameterList &ParameterList)=0 |
Updates internal variables. | |
virtual const Epetra_LinearProblem * | GetProblem () const =0 |
Returns the Epetra_LinearProblem. | |
virtual bool | MatrixShapeOK () const =0 |
Returns true if the solver can handle this matrix shape. | |
virtual const Epetra_Comm & | Comm () const =0 |
Returns a pointer to the Epetra_Comm communicator associated with this operator. | |
virtual int | NumSymbolicFact () const =0 |
Returns the number of symbolic factorizations performed by this object. | |
virtual int | NumNumericFact () const =0 |
Returns the number of numeric factorizations performed by this object. | |
virtual int | NumSolve () const =0 |
Returns the number of solves performed by this object. | |
virtual void | PrintStatus () const =0 |
Prints status information about the current solver. | |
virtual void | PrintTiming () const =0 |
Prints timing information about the current solver. | |
virtual void | setParameterList (Teuchos::RCP< Teuchos::ParameterList > const ¶mList) |
Redefined from Teuchos::ParameterListAcceptor. | |
virtual Teuchos::RCP < Teuchos::ParameterList > | getNonconstParameterList () |
This is an empty stub. | |
virtual Teuchos::RCP < Teuchos::ParameterList > | unsetParameterList () |
This is an empty stub. | |
virtual void | GetTiming (Teuchos::ParameterList &TimingParameterList) const |
Extracts timing information from the current solver and places it in the parameter list. |
Amesos_BaseSolver: A pure virtual class for direct solution of real-valued double-precision operators.
Pure virtual class for all Amesos concrete implementions.
The Amesos_BaseSolver class is a pure virtual class (that is, it specifies interface only) that enables the use of real-valued double-precision direct sparse solvers. Every Amesos class named Amesos_SolverName derives from Amesos_BaseSolver.
The basic calling sequence solves A x = b or A^{T} x = b without specifying how A has changed between each call to Solve().
Epetra_LinearProblem Problem(A,X,B); Amesos_SolverName Solver(Problem); Problem.SetUseTranspose(false); while( ... ) { <Here code which may change A or B> Solver.SymbolicFactorization(); Solver.NumericFactorization(); Solver.Solve(); }
The following calling sequence performs multiple solves of A x = b or A^{T} x = b in cases where the non-zero structure of A remains unchanged between each call to Solve().
Epetra_LinearProblem Problem(A,X,B); Amesos_SolverName Solver(Problem); Problem.SetUseTranspose(false); Solver.SymbolicFactorization(); while( ... ) { <Here code which may change B or the non-zero values (but not the non-zero structure) of A> Solver.NumericFactorization() ; Solver.Solve() ; }
The following calling sequence performs multiple solves of A x = b or A^{T} x = b provided that A remains unchanged between each call to Solve().
Epetra_LinearProblem Problem(A,X,B); Amesos_SolverName Solver(Problem); Problem.SetUseTranspose( false ); Solver.NumericFactorization(); while( ... ) { <Here code which may change B but not A> Solver.Solve(); }
Every Amesos_SolverName class should accept an Epetra_LinearProblem
Four mathematical methods are defined in the base class Amesos_BaseSolver: SymbolicFactorization(), NumericFactorization(), and Solve().
Different concrete classes, each based on a different third party solver, will have different performance characteristics and will accept different parameters.
Any changes to the values of a matrix must be accompanied by a call to NumericFactorization() before the next call to Solve() or the behavior of Solve() is undefined. Any changes to the numerical structure of the matrix must be followed by a call to SymbolicFactorization() and NumericalFactorization() before the next call to Solve().
Once SymbolicFactorization() has been called, classes implementing this interface may assume that any change made to the non-zero structure of the underlying matrix will be accompanied by a call to SymbolicFactorization() prior to a subsequent call to NumericFactorization or Solve().
Parameters can be changed or added at any time by calling SetParameters(ParamList) with the new parameters specified in ParamList.
It is left to the user to be sure that changes made to the parameters are appropriate for the concrete class that they are using.
Examples of appropriate changes in parameters include:
Examples of inappropriate changes in parameters include:
Solver.NumericFactorization(); Solver.getList()->set("DropTolerance",.001); Solver.Solve();
Results of making inappropriate changes in parameters is unpredictable and could include an error return, a bogus result or ignoring the parameter change.
Any class implementing Amesos_BaseSolver should handle calls to SetUseTranspose() at any point. However, the result of a call to SetUseTranspose() which is not followed by a call to SymbolicFactorization() and NumericFactorization() is implementation dependent. Some third party libraries are able to solve A^{T} x = b and Ax = b using the same factorization. Others will require a new factorization anytime that a call to SetUseTranspose() changes the intended solve from A^{T} x = b to Ax = b or vice-versa.
The following is a list of performance guidelines that classes which implement the Amesos_BaseSolver class are expected to maintain.
For serial codes, no more than one extra copy of the original matrix should be required. Except that some codes require matrix transpostion which requires additional copies of the input matrix.
For distributed memory codes, no serial copies of the original matrix should be required.
Failures should be caught by AMESOS_CHK_ERR(). The following error codes should be used:
Because we do not check to see if a matrix has changed between the call to SymbolicFactorization() and the call to NumericFactorization(), it is possible that a change to the matrix will cause a potentially catastrophic error.
virtual const Epetra_LinearProblem* Amesos_BaseSolver::GetProblem | ( | ) | const [pure virtual] |
Returns the Epetra_LinearProblem.
Warning! Do not call return->SetOperator(...)
to attempt to change the Epetra_Operator
object (even if the new matrix has the same structure). This new operator matrix will be ignored!
Implemented in Amesos_Btf, Amesos_Dscpack, Amesos_Klu, Amesos_Lapack, Amesos_Merikos, Amesos_Mumps, Amesos_Paraklete, Amesos_Pardiso, Amesos_Scalapack, Amesos_Superlu, Amesos_Superludist, Amesos_Taucs, and Amesos_Umfpack.
virtual bool Amesos_BaseSolver::MatrixShapeOK | ( | ) | const [pure virtual] |
Returns true if the solver can handle this matrix shape.
Returns true if the matrix shape is one that the underlying sparse direct solver can handle. Classes that work only on square matrices should return false for rectangular matrices. Classes that work only on symmetric matrices whould return false for non-symmetric matrices.
Implemented in Amesos_Btf, Amesos_Dscpack, Amesos_Klu, Amesos_Lapack, Amesos_Merikos, Amesos_Mumps, Amesos_Paraklete, Amesos_Pardiso, Amesos_Scalapack, Amesos_Superlu, Amesos_Superludist, Amesos_Taucs, and Amesos_Umfpack.
virtual int Amesos_BaseSolver::NumericFactorization | ( | ) | [pure virtual] |
Performs NumericFactorization on the matrix A.
In addition to performing numeric factorization on the matrix A, the call to NumericFactorization() implies that no change will be made to the underlying matrix without a subsequent call to NumericFactorization().
<br >Preconditions:
<br >Postconditions:
Implemented in Amesos_Btf, Amesos_Dscpack, Amesos_Klu, Amesos_Lapack, Amesos_Merikos, Amesos_Mumps, Amesos_Paraklete, Amesos_Pardiso, Amesos_Scalapack, Amesos_Superlu, Amesos_Superludist, Amesos_Taucs, and Amesos_Umfpack.
virtual int Amesos_BaseSolver::SetParameters | ( | Teuchos::ParameterList & | ParameterList | ) | [pure virtual] |
Updates internal variables.
<br >Preconditions:
<br >Postconditions:
Implemented in Amesos_Btf, Amesos_Dscpack, Amesos_Klu, Amesos_Lapack, Amesos_Merikos, Amesos_Mumps, Amesos_Paraklete, Amesos_Pardiso, Amesos_Scalapack, Amesos_Superlu, Amesos_Superludist, Amesos_Taucs, and Amesos_Umfpack.
virtual int Amesos_BaseSolver::SetUseTranspose | ( | bool | UseTranspose | ) | [pure virtual] |
If set true, X will be set to the solution of A^{T} X = B (not A X = B).
If the implementation of this interface does not support transpose use, this method should return a value of -1.
<br >Preconditions:
<br >Postconditions:
UseTranspose | -- (In) If true, solve A^{T} X = B, otherwise solve A X = B. |
Implemented in Amesos_Btf, Amesos_Dscpack, Amesos_Klu, Amesos_Lapack, Amesos_Merikos, Amesos_Mumps, Amesos_Paraklete, Amesos_Pardiso, Amesos_Scalapack, Amesos_Superlu, Amesos_Superludist, Amesos_Taucs, and Amesos_Umfpack.
virtual int Amesos_BaseSolver::Solve | ( | ) | [pure virtual] |
Solves A X = B (or A^{T} x = B).
<br >Preconditions:
<br >Postconditions:
Implemented in Amesos_Btf, Amesos_Dscpack, Amesos_Klu, Amesos_Lapack, Amesos_Merikos, Amesos_Mumps, Amesos_Paraklete, Amesos_Pardiso, Amesos_Scalapack, Amesos_Superlu, Amesos_Superludist, Amesos_Taucs, and Amesos_Umfpack.
virtual int Amesos_BaseSolver::SymbolicFactorization | ( | ) | [pure virtual] |
Performs SymbolicFactorization on the matrix A.
In addition to performing symbolic factorization on the matrix A, the call to SymbolicFactorization() implies that no change will be made to the non-zero structure of the underlying matrix without a subsequent call to SymbolicFactorization().
<br >Preconditions:
<br >Postconditions:
Implemented in Amesos_Btf, Amesos_Dscpack, Amesos_Klu, Amesos_Lapack, Amesos_Merikos, Amesos_Mumps, Amesos_Paraklete, Amesos_Pardiso, Amesos_Scalapack, Amesos_Superlu, Amesos_Superludist, Amesos_Taucs, and Amesos_Umfpack.