AMIGOS (Fig. 4.1) is a problem independent simulation system which can handle a wide range of nonlinear partial differential equation systems in time and space in either one, two or three dimension(s). It is designed to automatically generate optimized numerical models from a simple mathematical input language, so that no significant speed loss in comparison to `hand coded' standard simulation tools occurs.
In difference to similar algorithms based on the so called `operator on demand' concept [Yer95], AMIGOS is completely independent of the kind of discretization since the model developer can formulate any discretization of choice. There are no restrictions whether using scalar, field or tensor quantities within a model, and, if desired, any derived field quantity can be calculated, too. Furthermore, the user can influence the numerical behavior of the differential equation system by complete control of the residual vector and its derivative (e.g. punishing terms, damping terms, etc.). Even interpolation and grid-adaptation formulations can be used within a developed model and can thus be very well fitted to a special problem.
AMIGOS is equipped with three layers of access to serve the needs of the variety of users (Fig. 4.2).
In contrast with previous generations of software just the platform developer requires access to and modification of the source code. Even during model development the analytical user input will be interpreted, optimized, transformed and solved on any complex simulation domain at once without the necessity of time consuming recompilations (one-pass concept) supporting a variety of several testing and debugging features. After finishing the test and calibration phase the user can switch to the two-pass concept where all modifications are translated to C-code and are linked to a model library for high performance calculations on large simulation domains in the standard user-mode.