Issues on Behavior in Dynamic Geometry

Prof. Robert Joan-Arinyo
Universitat Politècnica de Catalunya
Escola Tècnica Superior d'Enginyeria Industrial de Barcelona


Dynamic Geometry systems are tools for geometric visualization. They allow the user to define geometric elements, establish relationships between them and explore the dynamic behavior of the remaining geometric elements when one of them is moved.

The main problem in Dynamic Geometry is the ambiguity that arises from operations which lead to more than one possible solution. Nowadays, most Dynamic Geometry systems deal with this problem in such a way that the solution selection method leads to a fixed dynamic behavior of the system. This is specially annoying when the behavior observed is not the one the user intended.

In the talk we first will recall basic, well established results that Geometric Constraint Solving and Dynamic Geometry share. Then we briefly overview continuity, determinism and conservationism properties in Dynamic Geometry. Next we will detail our concept of dynamic behavior. We will close with a short demo of the dynBCN Dynamic Geometry system prototype developed in our research group.