Thyra Operator/Vector Base Support Subclasses for MPI-based SPMD Thyra Implementations
[Thyra Operator/Vector Subclasses for MPI-based SPMD Distributed-Memory Platforms]

The package Thyra contains base subclasses that support a common type of MPI-based SPMD implementation of vectors and multi-vectors that are described here. More...

Classes
class	Thyra::MPILinearOpBase< Scalar >
	Base subclass for simplistic MPI SPMD linear operators. More...
class	Thyra::MPIMultiVectorBase< Scalar >
	Base class for MPI-based SPMD multi-vectors. More...
class	Thyra::MPIVectorBase< Scalar >
	Base class for MPI-based SPMD vectors. More...
class	Thyra::MPIVectorSpaceBase< Scalar >
	Base VectorSpaceBase class for all MPI-based vector spaces with contiguous local storage. More...
class	Thyra::MultiVectorSerialization< Scalar >
	Concrete utility class for reading and writing MPI-based SPMD MultiVectorBase objects to and from standard streams. More...

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Detailed Description

The package Thyra contains base subclasses that support a common type of MPI-based SPMD implementation of vectors and multi-vectors that are described here.

The UML class diagram below shows the subclasses described here:

Support base subclasses for MPI SPMD distributed-memory Thyra implementations (Note: above graphic is not hyperlinked!)

The base subclasses described here provide support for a simple, yet general, category of MPI-based SPMD vectors, multi-vectors and vector spaces.

• Thyra::MPIVectorSpaceBase abstracts the the types of SPMD distributed-memory data distributions supported by these base subclasses. This vector space base class assumes a unique partitioning of vector and multi-vector elements to a set of processors where there exists no ghost elements.

• Thyra::MPIVectorBase is a base subclass for MPI-based SPMD Thyra::VectorBase objects. This class defines concrete implementations for the Thyra::VectorBase virtual functions applyOp(), getSubVector() const, freeSubVector() const, getSubVector() and commitSubVector(). These functions are implemented given explicit access to local processor elements as returned by the getLocalData() functions overridden in a subclass object.

• Thyra::MPIMultiVectorBase is a base subclass for MPI-based SPMD Thyra::MultiVectorBase objects. This class defines concrete implementations for the Thyra::MultiVectorBase virtual functions applyOp(), getSubMultiVector() const, freeSubMultiVector() const, getSubMultiVector() and commitSubMultiVector(). These functions are implemented given explicit access to local processor elements as returned by the getLocalData() functions overridden in a subclass object. In addition, this subclass derives from Thyra::EuclideanLinearOpBase so that any application-specific scalar product is automatically supported. The multi-vector version of Thyra::MPIMultiVectorBase::euclideanApply() is implemented by calling Teuchos::BLAS::GEMM() on each local processor to access level-3 BLAS. Therefore, if Teuchos is configured to link to optimized BLAS then this base subclass will provided a near optimal implementation of a MPI SPMD multi-vector.

One of the big advantages of deriving concrete MPI-based SPMD implementations from these base subclasses is that they provide automatic interoperability between different concrete subclasses. This type of automatic interoperability is demonstrated in ???this testing program???.

Base Subclasses for MPI Thyra::LinearOpBase Implementations

To facilitate the creation of concrete MPI linear operators the following simple but very general base class is supplied:

• Thyra::MPILinearOpBase is a general base subclass for MPI SPMD platforms that only requires concrete subclass implementations to override one function that accepts explicit local vector data.

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