Trilinos/EpetraExt: Extensions to Epetra

Development

Introduction

EpetraExt is a set of extensions to Epetra. To allow Epetra to remain focused on its primary functionality as a Linear Algebra object support, EpetraExt was created to maintain additional support for such capabilities as transformations (permutations, sub-block views, etc.), coloring support, and I/O. (EpetraExt also provided partitioning via Zoltan, but partitioning is better supported in the Isorropia package.)

Overview of EpetraExt

EpetraExt Classes

EpetraExt contains a number of classes. They can be categorized as follows:

• EpetraExt::Transform classes: These classes derive from EpetraExt::Transform allowing a common interface for transformation of epetra objects and migration of associated data.
  1. EpetraExt::Transform: Abstract base for transformation of object of type T to object of type U.

  2. EpetraExt::Transform_Composite: Allows the additive composition of EpetraExt::SameTypeTransform's.

  3. Convertors: EpetraExt::LinearProblem_GraphTrans and EpetraExt::LinearProblem_MatrixTrans converts a EpetraExt::SameTypeTransform<Epetra_CrsGraph> and EpetraExt::SameTypeTransform<Epetra_CrsMatrix> to a EpetraExt::SameTypeTransform<Epetra_LinearProblem>

  4. EpetraExt::CrsGraph_Overlap: Forms the overlapped version of a distributed graph up to the user specified level.

  5. Reindexer's: Used to remap the global indexing of an existing Epetra object include EpetraExt::CrsMatrix_Reindex, EpetraExt::MultiVector_Reindex, and EpetraExt::LinearProblem_Reindex.

  6. EpetraExt::LinearProblem_Scale: Linear left and right scaling of a Epetra_LinearProblem

  7. Solver Mapping Tools: Remaps the columns of a CrsGraph or LinearProblem to meet the requirements of a square local block indexing for some linear solvers. Tools are EpetraExt::CrsGraph_SolverMap and EpetraExt::LinearProblem_SolverMap.

  8. EpetraExt::CrsGraph_SymmRCM: Perform a symmetric RCM for the local blocks of a Epetra_CrsGraph.

  9. Transpose: Form the explicit transpose of a Epetra_CrsGraph or Epetra_CrsMatrix. Tools are EpetraExt::CrsGraph_Transpose and EpetraExt::RowMatrix_Transpose.

  10. View: For sub-block views of existing Epetra objects including EpetraExt::CrsGraph_View, EpetraExt::CrsMatrix_View and EpetraExt::MultiVector_View

  11. Permutation: EpetraExt::Permutation is used for simple permutations of Epetra_CrsGraph, Epetra_CrsMatrix, and Epetra_MultiVector given a new Epetra_Map object.

EpetraExt Functions

• EpetraExt::MatrixMatrix: Static Matrix Matrix Operations including Multiply and Add.

• I/O Operations for Epetra Objects. Epetra supports I/O operations for Epetra objects based on
  1. Matlab triplet (i,j,value) format for writing and reading of Epetra RowMatrix and Operator objects.
  2. Matrix Market format: Support writing and reading of Epetra BlockMap, Map, MultiVector, Vector, RowMatrix and Operator objects.
  3. HDF5 format: Support writing and reading of Epetra BlockMap, Map, MultiVector, Vector, RowMatrix and Operator objects. Available when EpetraExt is configured with --enable-epetraext-hdf5.
  4. An XML-compatible reader and writer is available when Teuchos is configures with --enable-teuchos-expat.

• Coloring: Helper tools for generating Finite Differencing Colorings of Linear Problems.

• Zoltan Tools: Deprecated. Use Isorropia instead.

• Matlab: Communication interface between Epetra and Matlab. Exports Epetra objects to Matlab and imports objects from Matlab. Sends user specified Matlab commands to the Matlab engine to modify the Matlab workspace which provides user interaction with the Matlab engine.

• Trilinos/PETSc Interface : Wrapper class intended for users who would like to use Trilinos preconditioners within their PETSc-based application.

• Nonlinear Model Evaluator: EpetraExt::ModelEvaluator provides an Epetra-specific interface to nonlinear models for use by equation solvers all the way up to optimization.

EpetraExt adapters

The EpetraExt package can also optionally support adapters to various interfaces. Support for these adapters can be turned on at configure time.

• EpetraExt/Thyra Adapters: These adapters implement various advanced Thyra interfaces in terms of EpetraExt code.

Browse all of Epetraext as a single doxygen collection

You can browse all of EpetraExt as a single doxygen collection. Warning, this is not the recommended way to learn about EpetraExt software. However, this is a good way to browse the directory structure of epetraext, to locate files, etc.

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