An Implementatio n of Extrapolation Codes in C

This report describes the new object oriented implementation of extrapolation codes (Eulex, Eulsim, Difex) for ordinary diieren-tial equations. The resulting C++ class library provides a simple and exible interface to these methods and incorporates advanced features like continuous output and order-stepsize freezing. The interface of the ODE classes allows in particular a user-deened solver for the linear systems occuring in the linearly implicit discretization scheme. The library also provides some classes for numerical objects such as vectors and (full) matrices. Due to the underlying data-view concept it is possible to access substructures without copying. In addition, we included several utility classes such as a timer and a minimal command language that may be useful in other contexts, too.