Content Examples and Tutorial Scope of this Branch Compiler Requirements Git It/Download Mailing List Contributors Contributors

FLENS

FLENS is short for Flexible Library for Efficient Numerical Solutions. And that's exactly what it is:

A builing block for the implementation of other (higher-level) numerical libraries or numerical applications

Some key points

• C++ library (requires a C++11 conform compiler)

• Easy install as FLENS is headers only

• FLENS gives you

  • Matrix/vector types for dense linear algebra

  • Generic implementation of BLAS (see CXXBLAS)

  • Generic reimplementation of LAPACK (see FLENS-LAPACK)

  • Generic implementation means that you can use any element type for your matrices/vectors that “acts like a double”. So in particular types from the QD Library, mpfr, ...

• If high performance BLAS libraries like ATLAS or GotoBLAS are available:

  • compile with -DWITH_ATLAS or -DWITH_GOTOBLAS respectively,

  • link against them and boost performance.

  FLENS does not introduce any overhead due to abstraction. You get all the performance.

• FLENS-BLAS is a high-level and easy-to-use BLAS interface

• FLENS-LAPACK is a high-level and easy-to-use C++ implementation of LAPACK.

• FLENS also allows using overloaded operators for accessing BLAS. Most important in this respect:

  • Overloaded operators come without performance penalty!

  • In a special debug mode you can exactly trace what is happening and how you linear algebra expressions gets evaluated through BLAS calls

  • More features are explained in the tutorial.

Examples and Tutorial

• Overview of all driver functions currently implemented in FLENS-LAPACK

• We just started with a tutorial:

  • Session 1: General matrices and dense vectors.

  • Session 2: BLAS, CXXBLAS, FLENS-BLAS and Overloaded Operators.

  • Session 3: More on matrices: Triangular and symmetric matrices, matrix views, ...

  • Session 4: Using FLENS-LAPACK.

  • Session 5: Using an external LAPACK implementation.

  • Session 6: Sparse Matrices (Experimental).

  • Session 7: User Defined Matrix Types.

Scope of this Branch

• Real and complex matrix types with full storage and dense vector types, i.e.

  • GeMatrix,

  • SyMatrix,

  • TrMatrix,

  • DenseVector.

• Sparse matrices are experimental at the moment.

• Our generic BLAS implementation CXXBLAS.

• Support for high and multipecission types from QD Library and mpfr.

• Support for native BLAS implementations like ATLAS or GotoBLAS.

• FLENS-BLAS and FLENS-LAPACK.

• Overloaded operators for BLAS working ontop of the FLENS-BLAS layer.

• We improved our DocTool (look at the bottom of each page for document source). We now use restructured text.

Compiler Requirements

FLENS uses some of the C++11 features and therefore requires a recent C++ compiler:

• clang version 3.0 (or higher)

• gcc version 4.7 (or higher)

• icc version 12.1.2 (or higher)

Git It/Download

You can clone a public branch from GitHub

or download a snapshot.

Mailing List

Join the mailing list!

Contributors

• Michael Lehn

• Klaus Pototzky

• Alexander Stippler

Contributors

• Iris Häcker

• Michael Lehn

• Klaus Pototzky

• Alexander Stippler

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© 2011-2012 Michael Lehn