Debugging of equation systems

Currently, few or no tools are available to assist developers when debugging declarative equation based modeling languages. We have developed an debugging framework for Modelica and have adapted traditional debugging techniques and algorithms to it. The developed algorithms and methods

• are performed statically, before actual model execution of simulation.
• detect extra variables in underconstrained equation system
• detect extra equations in overconstrained equation system
• gives instructions on repair of the system.

Several simulation models and examples are given in the paper in order to illustrate the main situations when over and under-constraining equations can appear in the system. Error detection and error solving strategies for those cases are also given.

• Paper: Peter Bunus, Peter Fritzson, Methods for Structural Analysis and Debugging of Modelica Models (PDF), Proc. of 2nd Modelica Conference, 2002.
• Other papers are available from the author's home page.
• Supported by VISP (Vinnova) project
  
• Contact: Peter Bunus, petbu [at] ida.liu.se