FEMLISP - a Common Lisp Framework for Finite Element Methods

Short description:

FEMLISP is a framework for solving partial differential equations with the help of the finite element method (FEM). It is written completely in Common Lisp. In contrast to other approaches this has the following advantages:

• Common Lisp is a very expressive programming language which supports a multitude of programming styles: machine-oriented, imperative, functional, object-oriented - whatever you want. Therefore, for large projects, Common Lisp sourcecode is usually much shorter than sourcecode for handling the same problem in another language.

• There is no need for a separate scripting language, because Lisp is used anyhow in an interactive environment and is suited very well to the tasks of a scripting language. However, unlike interpreted scripting languages (e.g. Perl, Python, Tcl), Common Lisp code can be as efficient as equivalent C code.

• Using Emacs with SLIME yields a powerful Common Lisp development environment.

• Matlisp yields integration of the BLAS and LAPACK libraries.

• Some computer algebra systems (Axiom, Maxima) as well as several other AI tools are Common Lisp programs which can be integrated easily.

Functionality:

• Interactive environment
• Unstructured meshes in arbitrary space dimensions
• Cells are arbitrary products of simplices
• Automatic triangulation of 2D domains (interface to Triangle)
• Lagrange finite elements of arbitrary order
• Isoparametric and non-parametric cell mappings
• Error estimators and adaptive mesh refinement strategies
• Interfaces to direct solvers (SuperLU and UMFPACK)
• Geometric and algebraic multigrid methods
• Equations (diffusion-convection-reaction)
• Systems (elasticity, incompressible flow)
• Nonlinear problems
• Eigenvalue problems
• Time-dependent problems
• Integrated graphics (interfaces to OpenDX and Gnuplot)
• Integrated documentation, demonstrations, and tests
• Very liberal license (modified BSD)

Sample applications:

• Calculation of a permeability tensor
• Calculation of an effective elasticity tensor
• Calculation of a boundary law constant
• Calculation of a driven-cavity problem
• Calculation of an absorption process

Status: The current version of FEMLISP is 0-9-9. It has been tested and verified to work on Linux with CMUCL, SBCL, and Allegro CL, on Mac OS X with CMUCL and SBCL, on Solaris with CMUCL and SBCL, on a Linux/AMD64 system with Allegro CL and SBCL, and on Microsoft Windows using Allegro CL (however, you need a non-trial version of Allegro).

FEMLISP is hosted at Savannah. For more information, look at the User Manual.

Installation and download:

Follow the installation instructions in the User Manual.