Collection of abstracts 14th GAMM-Seminar Kiel on Concepts of Numerical Software January 23rd to 25th, 1998.

Friday, January 23rd, 1998

pdelib: An Open Modular Toolbox for the Numerical Solution of Partial Differential Equations

We discuss an object oriented software concept for the numerical solution of partial differential equations which has been implemented mainly in the C language. It is based on a bottom-up development strategy and does not standardize any high level structures as equations, boundary condition types or nonlinearities. Instead, data abstraction is done along basic building blocks like iterations, matrices and grids. An operator based interface concept allows a wide range of combinations of these structures.

At the same time the data structure and interface design has been performed in such a way that it is possible to integrate existing packages written in C++ or FORTRAN.

A general unstructured grid interface allows the utilization of grids generated off-line as well as of grids managed by an adaptive code like KASKADE (ZIB Berlin) or the grid generator IBG (WIAS Berlin). The grid structure is designed in such a way that it is possible to write code independent of the space dimension.

An OpenGL based online graphics package allows flexible graphical debugging at all stages of the code development process.

The design decisions taken allow for rapid prototyping within a wide range of applications and new, PDE based physical models. Examples are charge transport in semiconductors, porous media flow, hardening of steel.

At the current stage this toolbox is used to implement several industrial projects. This will give new feedback to the data abstraction process which thus will be strongly influenced by aspects of code development for engineering applications. A second future direction of development is the investigation of adaptive concepts which should behave modular and flexible and thus fit into the presented concept.